Why is === faster than == in PHP?
+42
A:
Because the equality operator == coerces, or converts the data type temporarily to see if it's equal to the other operand whereas === ( identity operator ) doesn't need to do any converting whatsoever and thus less work is done, making it faster.
meder
2010-03-08 13:16:14
@meder. I think your opinion is contrary with the what PHP Manual says. They say $a == $b is TRUE if $a is equal to $b, where $a === $b is TRUE if $a is equal to $b, and they are of the same type.
Bakhtiyor
2010-06-17 08:58:02
How is it contrary, then?
meder
2010-06-17 14:10:52
I believe it's actually that the 2 operands point to the same area of memory for complex types but meder's answer encompasses that
Basiclife
2010-08-24 19:21:18
+2
A:
I don't really know if it's significantly faster, but === in most languages is a direct type comparison, while == will try to do type coercion if necessary/possible to gain a match.
Chris
2010-03-08 13:16:31
"=== in most languages"? Name two other langauges that know "===" - bad news for you. I have never seen "===" before in any other languagae.
TomTom
2010-03-08 13:21:38
Javascript - not in 3 langauge definitions I checked ;) And Lisp and Scheme are many things, but hardly common ;)
TomTom
2010-03-08 13:29:02
@tomtom: http://www.webreference.com/js/column26/stricteq.html for javascript, http://phrogz.net/programmingruby/language.html#table_18.4 for ruby, etc... Try not to be an ass, k?
Chris
2010-03-08 13:32:51
ruby has ===. It has been too long for me to remember if it does the same thing.
KitsuneYMG
2010-03-08 13:33:01
Also, http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/operators.html for actionscript. Basically, google "strict equality".
Chris
2010-03-08 13:35:47
+8
A:
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
slightlymore
2010-03-08 13:16:46
I'd guess that `==` also checks the type first to see if any type conversion needs to be done. The fact that `===` doesn't do any conversion in the following step is what makes it faster.
deceze
2010-07-26 09:37:15
+1
A:
Because === doesn't need to coerce the operands to be of the same type before comparing them.
I doubt the difference in speed is very much though. Under normal circumstances you should use whichever operator makes more sense.
therefromhere
2010-03-08 13:17:30
+3
A:
=== does not perform typecasting, so 0 == '0' evaluates to true, but 0 === '0' - to false.
Raveren
2010-03-08 13:17:38
+1
A:
The == incurs a larger overhead of type conversion before comparison. === first checks the type, then proceeds without having to do any type conversion.
Martin
2010-03-08 13:18:18
A:
In conclusion === is faster because don't converts the data type to see if two variables have same value, but when you need to see if two variables have same value you will use == if doesen't mather what type are variables, or === if is important also the type of variables.
D.Martin
2010-03-09 20:03:34