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What is the difference between switch and ifelse in PHP? aiming at this problem, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible method.

Who is faster, switch or ifelse of PHP?

In the case of multiple if conditions, it will be clearer for the code to use switch instead of ifelse. What about their efficiency comparison? From the PHP manual, I found that someone had already compared it, and I also experimented with his code:

$s = time (); for ($I = 0; $I < 10000000000; + + $I) {$x = $I% 10; if ($x = = 1) {$y = $x * 1;} elseif ($x = 2) {$y = $x * 2;} elseif ($x = = 3) {$y = $x * 3;} elseif ($x = = 4) {$y = $x * 4;} elseif ($x = = 5) {$y = $x * 5 } elseif ($x = = 6) {$y = $x * 6;} elseif ($x = = 7) {$y = $x * 7;} elseif ($x = = 8) {$y = $x * 8;} elseif ($x = = 9) {$y = $x * 9;} else {$y = $x * 10;}} print ("if:". (time ()-$s). "sec\ n"); $s = time (); for ($I = 0; $I < 10000000000; + + $I) {$x = $I% 10; switch ($x) {case 1: $y = $x * 1; break; case 2: $y = $x * 2; break; case 3: $y = $x * 3; break Case 4: $y = $x * 4; break; case 5: $y = $x * 5; break; case 6: $y = $x * 6; break; case 7: $y = $x * 7; break; case 8: $y = $x * 8 Break; case 9: $y = $x * 9; break; default: $y = $x * 10;}} print ("switch:". (time ()-$s). "sec\ n")

After 1000000000 cycles and adding operations to each judgment condition, we found that switch is more efficient and faster, and the result on my computer is:

/ / if: 301sec// switch: 255sec

Although switch is more efficient, it also needs to be noted that, first of all, the judgment value can only be a number, a floating point number, or a string. Second, each judgment is an ordinary = = judgment, that is, the following judgment is not necessarily the result of your likeness:

$string = "2string"; switch ($string) {case 1: echo "this is 1"; break; case 2: echo "this is 2"; break; case '2stringing: echo "this is a string"; break;} / / this is 2

Yes, it is still the problem of type overturning when comparing = =. When comparing string and int values, it turns to int type, and the result of "2string" strong turning is exactly 2. Therefore, when using switch, you should make sure that the comparison values are consistent with the type of each case, otherwise unexpected errors may occur.

Reference code: https://github.com/zhangyue0503/dev-blog/blob/master/php/201911/source/PHP%E7%9A%84switch%E5%92%8Cifelse%E8%B0%81%E6%9B%B4%E5%BF%AB%EF%BC%9F.php on PHP switch and ifelse what is the difference between the questions shared here, I hope the above content can be of some help to you, if you still have a lot of doubts unsolved You can follow the industry information channel for more related knowledge.

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