Comparison of efficiency and performance between switch and ifelse in PHP_PHP Tutorial

We don’t need to introduce the difference between switch and ifelse. Here I will introduce to you the performance of switch and ifelse. When is it more suitable to use switch or ifelse?

There are two methods in PHP that are used to determine whether the value meets the conditions, and take different actions if it meets/is not met.

No matter what language you write a program in, you must consider the running efficiency of the code. After consulting some information, switch and ifelse each have superior efficiency in different 'environments'.

1. When the value being judged is a constant (fixed value), the operating efficiency of switch is higher than that of ifelse;

The code is as follows

代码如下	复制代码
$changliang=3;             // 变判断的值为常量 switch($changliang){     case 1:         echo '常量值为1';         break;             // 跳出循环     case 2:         echo '常量值为2';         break;     case 3:         echo '常量值为3';         break; }

Copy code

代码如下	复制代码
$a = $_GET['a'];            // 通过get传值后接值; 被判断的值 if($a=1){     echo '变量a的值为1'; }elseif($a=2){     echo '变量a的值为2'; }elseif($a=3){     echo '变量a的值为3'; }else{     echo '变量a的值为不知道'; }

$changliang=3; // Change the judged value to a constant
switch($changliang){
case 1:
echo 'The constant value is 1';
Break; // Break out of the loop
Case 2:
echo 'The constant value is 2';
          break;
case 3:
echo 'The constant value is 3';
          break;
}

2. When the judged value is a variable, the operating efficiency of ifelse is higher than that of switch. Ifelse implements the policy of judging from the first condition to the last else, so it is beneficial to learn to use switch;

The code is as follows

Copy code

$a = $_GET['a']; // Pass the value through get followed by the value; the value to be judged if($a=1){ echo 'The value of variable a is 1'; }elseif($a=2){ echo 'The value of variable a is 2'; }elseif($a=3){ echo 'The value of variable a is 3'; }else{ echo 'The value of variable a is unknown'; } http://www.bkjia.com/PHPjc/632684.html www.bkjia.comtruehttp: //www.bkjia.com/PHPjc/632684.htmlTechArticleWe don’t need to introduce the difference between switch and ifelse. Here I will introduce to you the performance of switch and ifelse. When is it more appropriate to use switch or ifelse? There are two methods in PHP...