My mistake with "strpos" function? php -

I get strpos to find the string variable $ string I'm trying to get the phrase "test" and if it is not defined as "test" another variable $ change is defined as $ string2 (where < Code> $ change pre-defined)

  if (strings ($ string, 'test') == incorrect) {$ change = $ string2; break; }  

But unfortunately it does not work.

Is there any mistake in the above?

Thank you.

Stops returns if you're using the === operator while comparing to use strokes.

  if (strings ($ string, 'test') === incorrect) {$ change = $ string2; break; }