# Shader:getExternVariable

Available since LÖVE 0.9.2
This function is not supported in earlier versions.

Gets information about an 'extern' ('uniform') variable in the shader.

Returns nil if the variable name doesn't exist in the shader, or if the video driver's shader compiler has determined that the variable doesn't affect the final output of the shader.

## Function

### Synopsis

    type, components, arrayelements = Shader:getExternVariable( name )

### Arguments

`string name`
  The name of the extern variable.

### Returns

`ShaderVariableType type (nil)`
  The base type of the variable.
`number components (nil)`
  The number of components in the variable (e.g. 2 for a vec2 or mat2.)
`number arrayelements (nil)`
  The number of elements in the array if the variable is an array, or 1 if not.

## See Also

- Shader
- Shader:send

##

Category:

- Functions