Example
Compare two strings (case sensitive):
<?php
echo strcmp("Hello world!","Hello world!");
?>
Definition and usage
strcmp() function compares two string.
Note: The strcmp() function is binary safe and case-sensitive.
Tip: This function is similar to the strncmp() function, except that with strncmp() you can specify the number of characters for each string to be compared.
Syntax
strcmp(string1,string2)
Parameters |
Description |
string1 |
Required. Specifies the first string to compare. |
string2 |
Required. Specifies the second string to be compared. |
Technical details
Return value: |
This function returns:
|
PHP version: | 4+ |
更多实例
实例 1
比较两个字符串(区分大小写,Hello 和 hELLo 输出不相同):
<?php
echo strcmp("Hello","Hello");
echo "<br>";
echo strcmp("Hello","hELLo");
?>
实例 2
不同的返回值:
<?php
echo strcmp("Hello world!","Hello world!"); // the two strings are equal
echo strcmp("Hello world!","Hello"); // string1 is greater than string2
echo strcmp("Hello world!","Hello world! Hello!"); // string1 is less than string2
?>
以区分大小写的方式比较两个字符串
Strcmp()函数对两个字符串进行二进制安全的比较,并区分大小写。其形式为:
int strcmp ( string str1 , string str2 )
根据比较的结果将返回如下的一个可能值。
•如果str1 和str2 相等则返回0 。
•如果str1小于str2则返回-1 。
•如果str1大于str2则返回1 。
网站经常要求待注册的用户输入并确认他选择的密码,减少由于键入错误而生成不正确密码的可能性。因为密码通常是区分大小写的,所以strcmp()对于比较这两个密码是非常合适的:
<?php
$pswd = "supersecret";
$pswd2 = "supersecret";
if (strcmp($pswd,$pswd2) != 0)
echo "Your passwords do not match!";
else
echo "Passwords match!";
?>
注意,对于strcmp ( ) ,字符串必须完全匹配才认为是相等的。例如,Supersecret 不同于supersecret 。如果要以不区分大小写的方式比较两个字符串,可以考虑下面介绍的strcasecmp ()。
关于这个函数,另一个容易混淆的地方是:两个字符串相等时要返回0 。这与使用==操作符完成字符串比较有所不同,如下:
if ( $str1 = = $str2)
两种方式目标相同,都是比较两个字符串,但要记住,它们返回的值却不同。
实例代码:
<?php
echo strcmp("Hello world!","Hello world!");
//返回0
?>
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