Replace(String, Target, Replacement)

Replace as its name indicates, replaces occurrences of a target substring with a given replacement.

Return value:
A new string where all the occurences of the target have been replaced.

Example:

a = "John went to buy a hamburger, because he likes ham." $
b = replace(a$, "ham", "cheese") $
print(b$)

John went to buy a cheeseburger, because he likes cheese.

Note: (especially to C programmers)
The replacement is not done directly in the string given. Instead, a new string is created.
So to replace correctly do:
var = replace(var$, target$, replacement$) $
And not: replace(var$, target$, replacement$)