How do i check if a substring matches with regex?

I want to find out if my string contains a certain substring and return true if it does and false if it doesnt.

regex = /^[a-z0-9]*(TEST)+'[a-z0-9]*$/;
if开发者_运维技巧(myString.contains(regex)) {
  // do something
}

With the ^ and $ anchors, you are pretty much preventing any sub-match, because they require the entire myString to match the regex. So the first step is to remove those anchors. Then:

if (regex.test(myString)) {