What does ^ mean in PHP?

Question

I came across this line of code in an application I am revising:

substr($sometext1 ^ $sometext2, 0, 512);

What does the ^ mean

Answer 1

In PHP, ^ means 'bitwise XOR'. Your code XORs together two strings, then returns at most the first 512 characters.

In other words it does this:

return (at most the first 512 characters of (someText1 XOR someText2))

Answer 2

XOR (exclusive OR):

$a ^ $b means bits that are set in $a or $b, but not both, are set.

Answer 3

It's a bitwise operator.

Example:

"hallo" ^ "hello"

It outputs the ASCII values #0 #4 #0 #0 #0 ('a' ^ 'e' = #4).

Answer 4

It's the XOR (exclusive-or) operator. For strings it's used as simple encryption.

Answer 5

^ matches the starting position within the string. In line-based tools, it matches the starting position of any line.

Answer 6

That's the bitwise OR operator - in PHP, it also applies to strings.