Functions

Test-Programm function_1.lua

function Test()
	print( "Hallo Welt" )
end

Test()

The Result:

Hallo Welt

Return values are defined with return.

Test-Programm function_3.lua

function test()
	return  "Hallo", "Welt"
end

v1, v2 = test()
print( v1 )
print( v2 )

The Result:

Hallo
Welt

Multiple return values are possible.

Test-Programm function_4.lua

function test()
	return  "Hallo", "Welt"
end

v = test()
print( v )

The Result:

Hallo

If you return multiple values without enough receivers, the additinal return values are ignored.

Test-Programm function_2.lua

function test()
	return  "Hallo Welt"
end

print ( test() )

The Result:

Hallo Welt

Functions with Parameter

Test-Programm function_par_1.lua

function summe( _v1, _v2)
	return  ( _v1 + _v2 )
end

print( summe( 1, 2 ) )
print( summe( 2, 3 ) )

The Result:

3
5

• Parameter start with _ (it's a convention, not a must)

Test-Programm function_par_2.lua

a = 'vorher'
function summe( _v1, _v2)
	a = _v1 + _v2
	return  a
end

print( summe( 1, 2 ) )
print( a )
print( _v1 )

The Result:

3
3
nil

• Parameter are local.
• Other variable are defined global.

Test-Programm function_par_3.lua

a = 'vorher'
function summe( _v1, _v2)
	local a = _v1 + _v2
	return  a
end

print( summe( 1, 2 ) )
print( a )
print( _v1 )

The Result:

3
vorher
nil

• If new varibales are defined with local, then they are only defined inside the block.