Analysis of usage examples of return in php_PHP tutorial

Example analysis of the usage of return in php

This article mainly introduces the usage of return in php. It analyzes the function and common usage skills of return in php with examples. It has certain For reference value, friends in need can refer to it

The example in this article describes the usage of return in php. Share it with everyone for your reference. The specific analysis is as follows:

First of all, it means return; return() is a language construct rather than a function, and it only needs to be enclosed in parentheses when the parameter contains an expression. Parentheses are usually not used when returning a variable, which can reduce the burden on PHP.

Basic usage:

a), return expression // Return an expression result
b), return(expr) // Function expression
c), return // Return directly, or return a null value

Note: It is best not to use return($val).

1. If return is executed, the content after the return statement will not be executed;

?

1 2 3 4 5 6

function add($a,$b){ return $a+$b; return $a*$b; } $c = add(5,3);//得到的$c值可以用在程序的其他地方！ echo $c;

1 2

3

4

5

6

1 2 3 4 5 6 7 8 9 10

function test($a){ if($a>10){ return "a>10"; }else{ return "a<10"; } $b=45; $c=$b-$a; echo $c; }

function add($a,$b){

return $a+$b;

return $a*$b;

}

$c = add(5,3);//The obtained $c value can be used in other places in the program!

echo $c;

1 2 3

$b=45; $c=$b-$a; echo $c;

Output result: 8, only $a+$b is executed, $a*$b is not executed.

2. Return can be a function return value or a null value, depending on the specific usage, for example:

?

1

1 2 3 4

include("b.php"); echo "a"; ?>

2 3

4

5

6

1 2 3 4

echo "b"; return; ?>

7 8

9

10

function test($a){

if($a>10){

1 2 3 4

include("b.php"); echo "a"; ?>

return "a>10"; }else{ return "a<10";<🎜> <🎜>}<🎜> <🎜>$b=45;<🎜> <🎜>$c=$b-$a;<🎜> <🎜>echo $c;<🎜> <🎜>}<🎜> <🎜>

<🎜> <🎜> <🎜> <🎜>In this example, when you call this function and give it any number, it will return a string, and the code: <🎜> <🎜> <🎜> <🎜> <🎜>?<🎜>

<🎜>1<🎜> <🎜>2<🎜> <🎜>3<🎜>

<🎜> <🎜>$b=45;<🎜> <🎜>$c=$b-$a;<🎜> <🎜>echo $c;<🎜> <🎜>

<🎜> <🎜> <🎜> <🎜> will never be executed. <🎜> <🎜>3. Regarding return calls. <🎜> <🎜>a.php is as follows: <🎜> <🎜> <🎜> <🎜> <🎜>?<🎜>

<🎜>1<🎜> <🎜>2<🎜> <🎜>3<🎜> <🎜>4<🎜>

<🎜> <🎜> <🎜>include("b.php");<🎜> <🎜>echo "a";<🎜> <🎜>?>

b.php is as follows: ?

1 2 3 4

<🎜>echo "b";<🎜> <🎜>return;<🎜> <🎜>?>

Output result: ba. a.php is as follows: ?

1 2 3 4

<🎜>include("b.php");<🎜> <🎜>echo "a";<🎜> <🎜>?>

b.php is as follows:

?

1 2 3 4

echo "b"; exit; // 结束整个当前脚本 ?>

1 2

3

4

echo "b";

exit; //End the entire current script

1 2 3 4 5 6

function test(){ $a=array(1,2); return $a; } $b=test(); print_r($b);

?>

Output result: a.

4. An important role of return: return value

Example 1:

1 2 3 4 5

function test(){ $a=array(1,2); } $b=test(); print_r($b);

?

1 2 3 4 5 6

function test(){ $a=array(1,2); return $a; } $b=test(); print_r($b);

Example 2: ?

1 2 3 4 5

function test(){ $a=array(1,2); } $b=test(); print_r($b);

Output results: Example 1 outputs normally, Example 2 outputs empty. Why? Because if you don't use return to return a value in the function rest(), there will only be a process in the function and no result to rest(). Of course, there will be no value output when the function is called. Of course, we can also write print_r($b) into test() and print directly in the function, but many times, we will call operations outside the function, so we need to use return to return a value to the outside. I hope this article will be helpful to everyone’s PHP programming design. http://www.bkjia.com/PHPjc/962407.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/962407.htmlTechArticleExample analysis of the usage of return in php. This article mainly introduces the usage of return in php and an example analysis of the usage of return in php. The function of return and common usage techniques have certain reference value. You need...

Statement of this Website

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn