Question

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Reference – What does this symbol mean in PHP?

When I was reading this php page, I was not sure what & is doing in $var & 1.

function odd($var)
{
    // returns whether the input integer is odd
    return($var & 1);
}

Is it returning a reference? I am not sure.

If you can explain it or direct me a php page, I will appreciate it.

Thanks in advance.

Answer 1

It’s a bitwise-AND operation. All odd numbers have LSB (least significant bit set to 1), even numbers – 0.

So it simply “ANDs” two numbers together. For example, 5. It is represented as 101 in binary. 101 & 001 = 001 => true, so it is odd.