Built-in GDScript functions. List of core built-in GDScript functions. Math functions and other utilities. Everything else is provided by objects. (Keywords: builtin, built in, global functions.) Returns a color constructed from integer red, green, blue, and alpha channels. Each channel should have 8 bits of information ranging from 0 to 255. [code]r8[/code] red channel [code]g8[/code] green channel [code]b8[/code] blue channel [code]a8[/code] alpha channel [codeblock] red = Color8(255, 0, 0) [/codeblock] Returns a color according to the standardized [code]name[/code] with [code]alpha[/code] ranging from 0 to 1. [codeblock] red = ColorN("red", 1) [/codeblock] Supported color names are the same as the constants defined in [Color]. Returns the absolute value of parameter [code]s[/code] (i.e. positive value). [codeblock] # a is 1 a = abs(-1) [/codeblock] Returns the arc cosine of [code]s[/code] in radians. Use to get the angle of cosine [code]s[/code]. [codeblock] # c is 0.523599 or 30 degrees if converted with rad2deg(s) c = acos(0.866025) [/codeblock] Returns the arc sine of [code]s[/code] in radians. Use to get the angle of sine [code]s[/code]. [codeblock] # s is 0.523599 or 30 degrees if converted with rad2deg(s) s = asin(0.5) [/codeblock] Asserts that the [code]condition[/code] is [code]true[/code]. If the [code]condition[/code] is [code]false[/code], an error is generated and the program is halted until you resume it. Only executes in debug builds, or when running the game from the editor. Use it for debugging purposes, to make sure a statement is [code]true[/code] during development. The optional [code]message[/code] argument, if given, is shown in addition to the generic "Assertion failed" message. You can use this to provide additional details about why the assertion failed. [codeblock] # Imagine we always want speed to be between 0 and 20 speed = -10 assert(speed < 20) # True, the program will continue assert(speed >= 0) # False, the program will stop assert(speed >= 0 && speed < 20) # You can also combine the two conditional statements in one check assert(speed < 20, "speed = %f, but the speed limit is 20" % speed) # Show a message with clarifying details [/codeblock] Returns the arc tangent of [code]s[/code] in radians. Use it to get the angle from an angle's tangent in trigonometry: [code]atan(tan(angle)) == angle[/code]. The method cannot know in which quadrant the angle should fall. See [method atan2] if you have both [code]y[/code] and [code]x[/code]. [codeblock] a = atan(0.5) # a is 0.463648 [/codeblock] Returns the arc tangent of [code]y/x[/code] in radians. Use to get the angle of tangent [code]y/x[/code]. To compute the value, the method takes into account the sign of both arguments in order to determine the quadrant. Important note: The Y coordinate comes first, by convention. [codeblock] a = atan2(0, -1) # a is 3.141593 [/codeblock] Decodes a byte array back to a value. When [code]allow_objects[/code] is [code]true[/code] decoding objects is allowed. [b]WARNING:[/b] Deserialized object can contain code which gets executed. Do not use this option if the serialized object comes from untrusted sources to avoid potential security threats (remote code execution). Converts a 2D point expressed in the cartesian coordinate system (X and Y axis) to the polar coordinate system (a distance from the origin and an angle). Rounds [code]s[/code] upward (towards positive infinity), returning the smallest whole number that is not less than [code]s[/code]. [codeblock] i = ceil(1.45) # i is 2 i = ceil(1.001) # i is 2 [/codeblock] See also [method floor], [method round], and [method stepify]. Returns a character as a String of the given Unicode code point (which is compatible with ASCII code). [codeblock] a = char(65) # a is "A" a = char(65 + 32) # a is "a" a = char(8364) # a is "€" [/codeblock] This is the inverse of [method ord]. Clamps [code]value[/code] and returns a value not less than [code]min[/code] and not more than [code]max[/code]. [codeblock] speed = 1000 # a is 20 a = clamp(speed, 1, 20) speed = -10 # a is 1 a = clamp(speed, 1, 20) [/codeblock] Converts from a type to another in the best way possible. The [code]type[/code] parameter uses the [enum Variant.Type] values. [codeblock] a = Vector2(1, 0) # Prints 1 print(a.length()) a = convert(a, TYPE_STRING) # Prints 6 as "(1, 0)" is 6 characters print(a.length()) [/codeblock] Returns the cosine of angle [code]s[/code] in radians. [codeblock] # Prints 1 then -1 print(cos(PI * 2)) print(cos(PI)) [/codeblock] Returns the hyperbolic cosine of [code]s[/code] in radians. [codeblock] # Prints 1.543081 print(cosh(1)) [/codeblock] Converts from decibels to linear energy (audio). Deprecated alias for [method step_decimals]. Returns the result of [code]value[/code] decreased by [code]step[/code] * [code]amount[/code]. [codeblock] # a = 59 a = dectime(60, 10, 0.1)) [/codeblock] Converts an angle expressed in degrees to radians. [codeblock] # r is 3.141593 r = deg2rad(180) [/codeblock] Converts a previously converted instance to a dictionary, back into an instance. Useful for deserializing. Easing function, based on exponent. The curve values are: 0 is constant, 1 is linear, 0 to 1 is ease-in, 1+ is ease out. Negative values are in-out/out in. The natural exponential function. It raises the mathematical constant [b]e[/b] to the power of [code]s[/code] and returns it. [b]e[/b] has an approximate value of 2.71828. For exponents to other bases use the method [method pow]. [codeblock] a = exp(2) # Approximately 7.39 [/codeblock] Rounds [code]s[/code] downward (towards negative infinity), returning the largest whole number that is not more than [code]s[/code]. [codeblock] # a is 2.0 a = floor(2.99) # a is -3.0 a = floor(-2.99) [/codeblock] See also [method ceil], [method round], and [method stepify]. [b]Note:[/b] This method returns a float. If you need an integer, you can use [code]int(s)[/code] directly. Returns the floating-point remainder of [code]a/b[/code], keeping the sign of [code]a[/code]. [codeblock] # Remainder is 1.5 var remainder = fmod(7, 5.5) [/codeblock] For the integer remainder operation, use the % operator. Returns the floating-point modulus of [code]a/b[/code] that wraps equally in positive and negative. [codeblock] for i in 7: var x = 0.5 * i - 1.5 print("%4.1f %4.1f %4.1f" % [x, fmod(x, 1.5), fposmod(x, 1.5)]) [/codeblock] Produces: [codeblock] -1.5 -0.0 0.0 -1.0 -1.0 0.5 -0.5 -0.5 1.0 0.0 0.0 0.0 0.5 0.5 0.5 1.0 1.0 1.0 1.5 0.0 0.0 [/codeblock] Returns a reference to the specified function [code]funcname[/code] in the [code]instance[/code] node. As functions aren't first-class objects in GDscript, use [code]funcref[/code] to store a [FuncRef] in a variable and call it later. [codeblock] func foo(): return("bar") a = funcref(self, "foo") print(a.call_func()) # Prints bar [/codeblock] Returns an array of dictionaries representing the current call stack. [codeblock] func _ready(): foo() func foo(): bar() func bar(): print(get_stack()) [/codeblock] would print [codeblock] [{function:bar, line:12, source:res://script.gd}, {function:foo, line:9, source:res://script.gd}, {function:_ready, line:6, source:res://script.gd}] [/codeblock] Returns the integer hash of the variable passed. [codeblock] print(hash("a")) # Prints 177670 [/codeblock] Returns the passed instance converted to a dictionary (useful for serializing). [codeblock] var foo = "bar" func _ready(): var d = inst2dict(self) print(d.keys()) print(d.values()) [/codeblock] Prints out: [codeblock] [@subpath, @path, foo] [, res://test.gd, bar] [/codeblock] Returns the Object that corresponds to [code]instance_id[/code]. All Objects have a unique instance ID. [codeblock] var foo = "bar" func _ready(): var id = get_instance_id() var inst = instance_from_id(id) print(inst.foo) # Prints bar [/codeblock] Returns a normalized value considering the given range. This is the opposite of [method lerp]. [codeblock] var middle = lerp(20, 30, 0.75) # `middle` is now 27.5. # Now, we pretend to have forgotten the original ratio and want to get it back. var ratio = inverse_lerp(20, 30, 27.5) # `ratio` is now 0.75. [/codeblock] Returns [code]true[/code] if [code]a[/code] and [code]b[/code] are approximately equal to each other. Returns whether [code]s[/code] is an infinity value (either positive infinity or negative infinity). Returns whether [code]instance[/code] is a valid object (e.g. has not been deleted from memory). Returns whether [code]s[/code] is a NaN ("Not a Number" or invalid) value. Returns [code]true[/code] if [code]s[/code] is zero or almost zero. This method is faster than using [method is_equal_approx] with one value as zero. Returns length of Variant [code]var[/code]. Length is the character count of String, element count of Array, size of Dictionary, etc. [b]Note:[/b] Generates a fatal error if Variant can not provide a length. [codeblock] a = [1, 2, 3, 4] len(a) # Returns 4 [/codeblock] Linearly interpolates between two values by a normalized value. This is the opposite of [method inverse_lerp]. If the [code]from[/code] and [code]to[/code] arguments are of type [int] or [float], the return value is a [float]. If both are of the same vector type ([Vector2], [Vector3] or [Color]), the return value will be of the same type ([code]lerp[/code] then calls the vector type's [code]linear_interpolate[/code] method). [codeblock] lerp(0, 4, 0.75) # Returns 3.0 lerp(Vector2(1, 5), Vector2(3, 2), 0.5) # Returns Vector2(2, 3.5) [/codeblock] Linearly interpolates between two angles (in radians) by a normalized value. Similar to [method lerp], but interpolates correctly when the angles wrap around [constant @GDScript.TAU]. [codeblock] extends Sprite var elapsed = 0.0 func _process(delta): var min_angle = deg2rad(0.0) var max_angle = deg2rad(90.0) rotation = lerp_angle(min_angle, max_angle, elapsed) elapsed += delta [/codeblock] Converts from linear energy to decibels (audio). This can be used to implement volume sliders that behave as expected (since volume isn't linear). Example: [codeblock] # "Slider" refers to a node that inherits Range such as HSlider or VSlider. # Its range must be configured to go from 0 to 1. # Change the bus name if you'd like to change the volume of a specific bus only. AudioServer.set_bus_volume_db(AudioServer.get_bus_index("Master"), linear2db($Slider.value)) [/codeblock] Loads a resource from the filesystem located at [code]path[/code]. The resource is loaded on the method call (unless it's referenced already elsewhere, e.g. in another script or in the scene), which might cause slight delay, especially when loading scenes. To avoid unnecessary delays when loading something multiple times, either store the resource in a variable or use [method preload]. [b]Note:[/b] Resource paths can be obtained by right-clicking on a resource in the FileSystem dock and choosing "Copy Path" or by dragging the file from the FileSystem dock into the script. [codeblock] # Load a scene called main located in the root of the project directory and cache it in a variable. var main = load("res://main.tscn") # main will contain a PackedScene resource. [/codeblock] [b]Important:[/b] The path must be absolute, a local path will just return [code]null[/code]. This method is a simplified version of [method ResourceLoader.load], which can be used for more advanced scenarios. Natural logarithm. The amount of time needed to reach a certain level of continuous growth. [b]Note:[/b] This is not the same as the "log" function on most calculators, which uses a base 10 logarithm. [codeblock] log(10) # Returns 2.302585 [/codeblock] Returns the maximum of two values. [codeblock] max(1, 2) # Returns 2 max(-3.99, -4) # Returns -3.99 [/codeblock] Returns the minimum of two values. [codeblock] min(1, 2) # Returns 1 min(-3.99, -4) # Returns -4 [/codeblock] Moves [code]from[/code] toward [code]to[/code] by the [code]delta[/code] value. Use a negative [code]delta[/code] value to move away. [codeblock] move_toward(10, 5, 4) # Returns 6 [/codeblock] Returns the nearest larger power of 2 for integer [code]value[/code]. [codeblock] nearest_po2(3) # Returns 4 nearest_po2(4) # Returns 4 nearest_po2(5) # Returns 8 [/codeblock] Returns an integer representing the Unicode code point of the given Unicode character [code]char[/code]. [codeblock] a = ord("A") # a is 65 a = ord("a") # a is 97 a = ord("€") # a is 8364 [/codeblock] This is the inverse of [method char]. Parse JSON text to a Variant. (Use [method typeof] to check if the Variant's type is what you expect.) [b]Note:[/b] The JSON specification does not define integer or float types, but only a [i]number[/i] type. Therefore, parsing a JSON text will convert all numerical values to [float] types. [b]Note:[/b] JSON objects do not preserve key order like Godot dictionaries, thus, you should not rely on keys being in a certain order if a dictionary is constructed from JSON. In contrast, JSON arrays retain the order of their elements: [codeblock] var p = JSON.parse('["hello", "world", "!"]') if typeof(p.result) == TYPE_ARRAY: print(p.result[0]) # Prints "hello" else: push_error("Unexpected results.") [/codeblock] See also [JSON] for an alternative way to parse JSON text. Converts a 2D point expressed in the polar coordinate system (a distance from the origin [code]r[/code] and an angle [code]th[/code]) to the cartesian coordinate system (X and Y axis). Returns the integer modulus of [code]a/b[/code] that wraps equally in positive and negative. [codeblock] for i in range(-3, 4): print("%2d %2d %2d" % [i, i % 3, posmod(i, 3)]) [/codeblock] Produces: [codeblock] -3 0 0 -2 -2 1 -1 -1 2 0 0 0 1 1 1 2 2 2 3 0 0 [/codeblock] Returns the result of [code]x[/code] raised to the power of [code]y[/code]. [codeblock] pow(2, 5) # Returns 32 [/codeblock] Returns a [Resource] from the filesystem located at [code]path[/code]. The resource is loaded during script parsing, i.e. is loaded with the script and [method preload] effectively acts as a reference to that resource. Note that the method requires a constant path. If you want to load a resource from a dynamic/variable path, use [method load]. [b]Note:[/b] Resource paths can be obtained by right clicking on a resource in the Assets Panel and choosing "Copy Path" or by dragging the file from the FileSystem dock into the script. [codeblock] # Instance a scene. var diamond = preload("res://diamond.tscn").instance() [/codeblock] Converts one or more arguments to strings in the best way possible and prints them to the console. [codeblock] a = [1, 2, 3] print("a", "b", a) # Prints ab[1, 2, 3] [/codeblock] [b]Note:[/b] Consider using [method push_error] and [method push_warning] to print error and warning messages instead of [method print]. This distinguishes them from print messages used for debugging purposes, while also displaying a stack trace when an error or warning is printed. Like [method print], but prints only when used in debug mode. Prints a stack track at code location, only works when running with debugger turned on. Output in the console would look something like this: [codeblock] Frame 0 - res://test.gd:16 in function '_process' [/codeblock] Prints one or more arguments to strings in the best way possible to standard error line. [codeblock] printerr("prints to stderr") [/codeblock] Prints one or more arguments to strings in the best way possible to console. No newline is added at the end. [codeblock] printraw("A") printraw("B") # Prints AB [/codeblock] [b]Note:[/b] Due to limitations with Godot's built-in console, this only prints to the terminal. If you need to print in the editor, use another method, such as [method print]. Prints one or more arguments to the console with a space between each argument. [codeblock] prints("A", "B", "C") # Prints A B C [/codeblock] Prints one or more arguments to the console with a tab between each argument. [codeblock] printt("A", "B", "C") # Prints A B C [/codeblock] Pushes an error message to Godot's built-in debugger and to the OS terminal. [codeblock] push_error("test error") # Prints "test error" to debugger and terminal as error call [/codeblock] [b]Note:[/b] Errors printed this way will not pause project execution. To print an error message and pause project execution in debug builds, use [code]assert(false, "test error")[/code] instead. Pushes a warning message to Godot's built-in debugger and to the OS terminal. [codeblock] push_warning("test warning") # Prints "test warning" to debugger and terminal as warning call [/codeblock] Converts an angle expressed in radians to degrees. [codeblock] rad2deg(0.523599) # Returns 30 [/codeblock] Random range, any floating point value between [code]from[/code] and [code]to[/code]. [codeblock] prints(rand_range(0, 1), rand_range(0, 1)) # Prints e.g. 0.135591 0.405263 [/codeblock] Random from seed: pass a [code]seed[/code], and an array with both number and new seed is returned. "Seed" here refers to the internal state of the pseudo random number generator. The internal state of the current implementation is 64 bits. Returns a random floating point value on the interval [code][0, 1][/code]. [codeblock] randf() # Returns e.g. 0.375671 [/codeblock] Returns a random unsigned 32 bit integer. Use remainder to obtain a random value in the interval [code][0, N - 1][/code] (where N is smaller than 2^32). [codeblock] randi() # Returns random integer between 0 and 2^32 - 1 randi() % 20 # Returns random integer between 0 and 19 randi() % 100 # Returns random integer between 0 and 99 randi() % 100 + 1 # Returns random integer between 1 and 100 [/codeblock] Randomizes the seed (or the internal state) of the random number generator. Current implementation reseeds using a number based on time. [codeblock] func _ready(): randomize() [/codeblock] Returns an array with the given range. Range can be 1 argument N (0 to N-1), two arguments (initial, final-1) or three arguments (initial, final-1, increment). [codeblock] print(range(4)) print(range(2, 5)) print(range(0, 6, 2)) [/codeblock] Output: [codeblock] [0, 1, 2, 3] [2, 3, 4] [0, 2, 4] [/codeblock] Maps a [code]value[/code] from range [code][istart, istop][/code] to [code][ostart, ostop][/code]. [codeblock] range_lerp(75, 0, 100, -1, 1) # Returns 0.5 [/codeblock] Rounds [code]s[/code] to the nearest whole number, with halfway cases rounded away from zero. [codeblock] round(2.6) # Returns 3 [/codeblock] See also [method floor], [method ceil], and [method stepify]. Sets seed for the random number generator. [codeblock] my_seed = "Godot Rocks" seed(my_seed.hash()) [/codeblock] Returns the sign of [code]s[/code]: -1 or 1. Returns 0 if [code]s[/code] is 0. [codeblock] sign(-6) # Returns -1 sign(0) # Returns 0 sign(6) # Returns 1 [/codeblock] Returns the sine of angle [code]s[/code] in radians. [codeblock] sin(0.523599) # Returns 0.5 [/codeblock] Returns the hyperbolic sine of [code]s[/code]. [codeblock] a = log(2.0) # Returns 0.693147 sinh(a) # Returns 0.75 [/codeblock] Returns a number smoothly interpolated between the [code]from[/code] and [code]to[/code], based on the [code]weight[/code]. Similar to [method lerp], but interpolates faster at the beginning and slower at the end. [codeblock] smoothstep(0, 2, 0.5) # Returns 0.15 smoothstep(0, 2, 1.0) # Returns 0.5 smoothstep(0, 2, 2.0) # Returns 1.0 [/codeblock] Returns the square root of [code]s[/code], where [code]s[/code] is a non-negative number. [codeblock] sqrt(9) # Returns 3 [/codeblock] If you need negative inputs, use [code]System.Numerics.Complex[/code] in C#. Returns the position of the first non-zero digit, after the decimal point. Note that the maximum return value is 10, which is a design decision in the implementation. [codeblock] # n is 0 n = step_decimals(5) # n is 4 n = step_decimals(1.0005) # n is 9 n = step_decimals(0.000000005) [/codeblock] Snaps float value [code]s[/code] to a given [code]step[/code]. This can also be used to round a floating point number to an arbitrary number of decimals. [codeblock] stepify(100, 32) # Returns 96 stepify(3.14159, 0.01) # Returns 3.14 [/codeblock] See also [method ceil], [method floor], and [method round]. Converts one or more arguments to string in the best way possible. [codeblock] var a = [10, 20, 30] var b = str(a); len(a) # Returns 3 len(b) # Returns 12 [/codeblock] Converts a formatted string that was returned by [method var2str] to the original value. [codeblock] a = '{ "a": 1, "b": 2 }' b = str2var(a) print(b["a"]) # Prints 1 [/codeblock] Returns the tangent of angle [code]s[/code] in radians. [codeblock] tan(deg2rad(45)) # Returns 1 [/codeblock] Returns the hyperbolic tangent of [code]s[/code]. [codeblock] a = log(2.0) # Returns 0.693147 tanh(a) # Returns 0.6 [/codeblock] Converts a [Variant] [code]var[/code] to JSON text and return the result. Useful for serializing data to store or send over the network. [codeblock] # Both numbers below are integers. a = { "a": 1, "b": 2 } b = to_json(a) print(b) # {"a":1, "b":2} # Both numbers above are floats, even if they display without any decimal places. [/codeblock] [b]Note:[/b] The JSON specification does not define integer or float types, but only a [i]number[/i] type. Therefore, converting a [Variant] to JSON text will convert all numerical values to [float] types. See also [JSON] for an alternative way to convert a [Variant] to JSON text. Returns whether the given class exists in [ClassDB]. [codeblock] type_exists("Sprite") # Returns true type_exists("Variant") # Returns false [/codeblock] Returns the internal type of the given Variant object, using the [enum Variant.Type] values. [codeblock] p = parse_json('["a", "b", "c"]') if typeof(p) == TYPE_ARRAY: print(p[0]) # Prints a else: print("unexpected results") [/codeblock] Checks that [code]json[/code] is valid JSON data. Returns an empty string if valid, or an error message otherwise. [codeblock] j = to_json([1, 2, 3]) v = validate_json(j) if not v: print("Valid JSON.") else: push_error("Invalid JSON: " + v) [/codeblock] Encodes a variable value to a byte array. When [code]full_objects[/code] is [code]true[/code] encoding objects is allowed (and can potentially include code). Converts a Variant [code]var[/code] to a formatted string that can later be parsed using [method str2var]. [codeblock] a = { "a": 1, "b": 2 } print(var2str(a)) [/codeblock] prints [codeblock] { "a": 1, "b": 2 } [/codeblock] Returns a weak reference to an object. A weak reference to an object is not enough to keep the object alive: when the only remaining references to a referent are weak references, garbage collection is free to destroy the referent and reuse its memory for something else. However, until the object is actually destroyed the weak reference may return the object even if there are no strong references to it. Wraps float [code]value[/code] between [code]min[/code] and [code]max[/code]. Usable for creating loop-alike behavior or infinite surfaces. [codeblock] # Infinite loop between 5.0 and 9.9 value = wrapf(value + 0.1, 5.0, 10.0) [/codeblock] [codeblock] # Infinite rotation (in radians) angle = wrapf(angle + 0.1, 0.0, TAU) [/codeblock] [codeblock] # Infinite rotation (in radians) angle = wrapf(angle + 0.1, -PI, PI) [/codeblock] [b]Note:[/b] If [code]min[/code] is [code]0[/code], this is equivalent to [method fposmod], so prefer using that instead. [code]wrapf[/code] is more flexible than using the [method fposmod] approach by giving the user control over the minimum value. Wraps integer [code]value[/code] between [code]min[/code] and [code]max[/code]. Usable for creating loop-alike behavior or infinite surfaces. [codeblock] # Infinite loop between 5 and 9 frame = wrapi(frame + 1, 5, 10) [/codeblock] [codeblock] # result is -2 var result = wrapi(-6, -5, -1) [/codeblock] [b]Note:[/b] If [code]min[/code] is [code]0[/code], this is equivalent to [method posmod], so prefer using that instead. [code]wrapi[/code] is more flexible than using the [method posmod] approach by giving the user control over the minimum value. Stops the function execution and returns the current suspended state to the calling function. From the caller, call [method GDScriptFunctionState.resume] on the state to resume execution. This invalidates the state. Within the resumed function, [code]yield()[/code] returns whatever was passed to the [code]resume()[/code] function call. If passed an object and a signal, the execution is resumed when the object emits the given signal. In this case, [code]yield()[/code] returns the argument passed to [code]emit_signal()[/code] if the signal takes only one argument, or an array containing all the arguments passed to [code]emit_signal()[/code] if the signal takes multiple arguments. You can also use [code]yield[/code] to wait for a function to finish: [codeblock] func _ready(): yield(countdown(), "completed") # waiting for the countdown() function to complete print('Ready') func countdown(): yield(get_tree(), "idle_frame") # returns a GDScriptFunctionState object to _ready() print(3) yield(get_tree().create_timer(1.0), "timeout") print(2) yield(get_tree().create_timer(1.0), "timeout") print(1) yield(get_tree().create_timer(1.0), "timeout") # prints: # 3 # 2 # 1 # Ready [/codeblock] When yielding on a function, the [code]completed[/code] signal will be emitted automatically when the function returns. It can, therefore, be used as the [code]signal[/code] parameter of the [code]yield[/code] method to resume. In order to yield on a function, the resulting function should also return a [code]GDScriptFunctionState[/code]. Notice [code]yield(get_tree(), "idle_frame")[/code] from the above example. Constant that represents how many times the diameter of a circle fits around its perimeter. This is equivalent to [code]TAU / 2[/code]. The circle constant, the circumference of the unit circle in radians. Positive infinity. For negative infinity, use -INF. "Not a Number", an invalid value. [code]NaN[/code] has special properties, including that it is not equal to itself. It is output by some invalid operations, such as dividing zero by zero.