What is the meaning of " |= " in php?

Question

I don't know what is the meaning of "|=" in php. Searching Google doesn't help. Please someone explain exactly what they do.

My Question is meaning of "|=" not "!=" ?

I have already search "Reference - What does this symbol mean in PHP?" but i did't get my answer.

Answer 1

This is bitwise OR operator

$var1 |= $var2; is equal to $var1 = $var1 | $var2;