### 28.6.8 Removing spaces from strings: an example

Suppose you need to remove spaces and apostrophes from a string value (such as a topic title), and replace each space with an underscore, sending the result to output. The following macro uses several macro expression features:

[NewString]

<$_repeat ($$OldString length)>\

<$$char = ($$OldString char $$_count)>\

<$_if ($$char is " ")>_\

<$_elseif ($$char is not "'"><$$char>\

<$_endif>\

<$_endrepeat>\

| 28.6.7 Using indirection in expressions |  | 28.7 Passing a parameter to a macro |