Internal functions/Boolean functions - Revision history

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2014-09-17T01:53:52Z

make redirect

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2013-05-09T21:33:33Z

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Gavino: Expand description of Defined()

2008-11-25T00:24:15Z

Expand description of Defined()

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== Boolean functions ==

These functions return true or false, if the condition that they test holds or not, respectively.

* {{ScriptFunction|IsBool||IsBool(var)}}
: Tests if ''var'' is of the bool type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
: ''Examples:''
b = false
IsBool(b) = true
IsBool(1 < 2 && 0 == 1) = true
IsBool(123) = false

* {{ScriptFunction|IsClip||IsClip(var)}}
: Tests if ''var'' is of the clip type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
: ''Examples:''
c = [[AviSource]](...)
IsClip(c) = true
IsClip("c") = false

* {{ScriptFunction|IsFloat||IsFloat(var)}}
: Tests if ''var'' is of the float type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
: ''Examples:''
f = [[Internal_functions/Numeric_functions|Sqrt]](2)
IsFloat(f) = true
IsFloat(2) = true # ints are considered to be floats by this function
IsFloat(true) = false

* {{ScriptFunction|IsInt||IsInt(var)}}
: Tests if ''var'' is of the int type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
: ''Examples:''
IsInt(2) = true
IsInt(2.1) = false
IsInt(true) = false

* {{ScriptFunction|IsString||IsString(var)}}
: Tests if ''var'' is of the string type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
: ''Examples:''
IsString("test") = true
IsString(2.3) = false
IsString([[Internal_functions/Conversion_functions|String]](2.3)) = true

* {{ScriptFunction|Exist|v2.07|Exist(filename)}}
: Tests if the file specified by ''filename'' exists.
: ''Examples:''
filename = ...
clp = Exist(filename) ? [[AviSource]](filename) : [[Internal_functions/Control_functions|Assert]](false, "file: " + filename + " does not exist")

* {{ScriptFunction|Defined||Defined(var)}}
: Tests if ''var'' is defined. Can be used inside [[Script_functions]] to test if an optional argument has been given an explicit value.
: More formally, the function returns false if its argument (normally a function argument or variable) has the void ('undefined') type, otherwise it returns true.
: ''Examples:''
b_arg_supplied = Defined(arg)
myvar = b_arg_supplied ? ... : ...

----
Back to [[Internal functions]].

[[Category:AviSynth_Syntax]]
[[Category:Scripting_Basics]]

@@ Line 1: / Line 1: @@
-== Boolean functions ==
+#REDIRECT [[Internal_functions#Boolean_functions]]
-−
-These functions return true or false, if the condition that they test holds or not, respectively.
-−
-* {{ScriptFunction|IsBool||IsBool(var)}}
-: Tests if ''var'' is of the bool type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
-: ''Examples:''
- b = false
- IsBool(b) = true
- IsBool(1 < 2 && 0 == 1) = true
- IsBool(123) = false
-−
-* {{ScriptFunction|IsClip||IsClip(var)}}
-: Tests if ''var'' is of the clip type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
-: ''Examples:''
- c = [[AviSource]](...)
- IsClip(c) = true
- IsClip("c") = false
-−
-* {{ScriptFunction|IsFloat||IsFloat(var)}}
-: Tests if ''var'' is of the float type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
-: ''Examples:''
- f = [[Internal_functions/Numeric_functions|Sqrt]](2)
- IsFloat(f) = true
- IsFloat(2) = true   # ints are considered to be floats by this function
- IsFloat(true) = false
-−
-* {{ScriptFunction|IsInt||IsInt(var)}}
-: Tests if ''var'' is of the int type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
-: ''Examples:''
- IsInt(2) = true
- IsInt(2.1) = false
- IsInt(true) = false
-−
-* {{ScriptFunction|IsString||IsString(var)}}
-: Tests if ''var'' is of the string type. ''var'' can be any expression allowed by the [[AviSynth Syntax]].
-: ''Examples:''
- IsString("test") = true
- IsString(2.3) = false
- IsString([[Internal_functions/Conversion_functions|String]](2.3)) = true
-−
-* {{ScriptFunction|Exist|v2.07|Exist(filename)}}
-: Tests if the file specified by ''filename'' exists.
-: ''Examples:''
- filename = ...
- clp = Exist(filename) ? [[AviSource]](filename) : [[Internal_functions/Control_functions|Assert]](false, "file: " + filename + " does not exist")
-−
-* {{ScriptFunction|Defined||Defined(var)}}
-: Tests if ''var'' is defined. Can be used inside [[Script_functions]] to test if an optional argument has been given an explicit value.
-: More formally, the function returns false if its argument (normally a function argument or variable) has the void ('undefined') type, otherwise it returns true.
-: ''Examples:''
- b_arg_supplied = Defined(arg)
- myvar = b_arg_supplied ? ... : ...
-−
-----
-Back to [[Internal functions]].
 [[Category:AviSynth_Syntax]]
 [[Category:Scripting_Basics]]