Difference between revisions of "Assert"
(added example) |
m (Text replacement - "</source" to "</syntaxhighlight") |
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<source lang="lua"> | <source lang="lua"> | ||
assert(v,message) | assert(v,message) | ||
| − | </ | + | </syntaxhighlight> |
''message'' is an error message, when absent it defaults to "assertion failed!". | ''message'' is an error message, when absent it defaults to "assertion failed!". | ||
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if isValidTexture() then bmp = Bitmap.new(Texture.new(texturepath)) end | if isValidTexture() then bmp = Bitmap.new(Texture.new(texturepath)) end | ||
end | end | ||
| − | </ | + | </syntaxhighlight> |
'''Checks if is of type ''number''''' | '''Checks if is of type ''number''''' | ||
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--local value = "hello" --> *** Friction must be a number *** | --local value = "hello" --> *** Friction must be a number *** | ||
assert(type(value) == 'number', "*** Friction must be a number ***") | assert(type(value) == 'number', "*** Friction must be a number ***") | ||
| − | </ | + | </syntaxhighlight> |
=== See also === | === See also === | ||
Revision as of 16:56, 12 July 2023
Available since: Gideros 2011.6
Class: (global)
Description
Issues an error when the value of its argument v is false (i.e.: nil or false), otherwise returns all its arguments. <source lang="lua"> assert(v,message) </syntaxhighlight>
message is an error message, when absent it defaults to "assertion failed!".
Parameters
v: (any) expression/function to assert
message: (string) error message if assert fails optional
Examples
Checks if a texture is valid <source lang="lua"> function isValidTexture() local result, msg = assert(Texture.new(texturepath), "file is not recognised") print(result, msg) return result end
function showTexture() if isValidTexture() then bmp = Bitmap.new(Texture.new(texturepath)) end end </syntaxhighlight>
Checks if is of type number <source lang="lua"> local value = 12 --> 12 --local value = "hello" --> *** Friction must be a number *** assert(type(value) == 'number', "*** Friction must be a number ***") </syntaxhighlight>
See also
