Why is === faster than == in PHP?

Question

Because the equality operator == coerces, or converts, the data type temporarily to see if it’s equal to the other operand, whereas === (the identity operator) doesn’t need to do any converting whatsoever and thus less work is done, which makes it faster.

=== does not perform typecasting, so 0 == '0' evaluates to true, but 0 === '0' - to false.

There are two things to consider:

1. If operand types are different then == and === produce different results. In that case the speed of the operators does not matter; what matters is which one produces the desired result.

2. If operand types are same then you can use either == or === as both will produce same results. In that case the speed of both operators is almost identical. This is because no type conversion is performed by either operators.

I compared the speed of:

• $a == $b vs $a === $b
• where $a and $b were random integers [1, 100]
• the two variables were generated and compared one million times
• the tests were run 10 times

And here are the results:

 $a == $b $a === $b
--------- ---------
 0.765770  0.762020
 0.753041  0.825965
 0.770631  0.783696
 0.787824  0.781129
 0.757506  0.796142
 0.773537  0.796734
 0.768171  0.767894
 0.747850  0.777244
 0.836462  0.826406
 0.759361  0.773971
--------- ---------
 0.772015  0.789120

You can see that the speed is almost identical.

First, === checks to see if the two arguments are the same type - so the number 1 and the string '1' fails on the type check before any comparisons are actually carried out. On the other hand, == doesn't check the type first and goes ahead and converts both arguments to the same type and then does the comparison.

Therefore, === is quicker at checking a fail condition