PHP strcmp,strnatcmp,strncmp函数的区别，strnatcmpstrncmp

PHP strcmp,strnatcmp,strncmp函数的区别，strnatcmpstrncmp

字符串比较说明
当s1
当s1=s2时，返回值= 0
当s1>s2时，返回正数

<span> 1</span> <?<span>php
</span><span> 2</span> <span>$str1</span> = 'str100'<span>;
</span><span> 3</span> <span>$str2</span> = 'str20'<span>;
</span><span> 4</span> <span>echo</span> <span>strcmp</span>(<span>$str1</span>, <span>$str2</span>)."<br>"<span>;
</span><span> 5</span> <span>//输出</span><span>-1</span>
<span> 6</span> <span>echo</span> <span>strnatcmp</span>(<span>$str1</span>, <span>$str2</span>)."<br>"<span>;
</span><span> 7</span> <span>//输出</span><span>1</span>
<span> 8</span> <span>echo</span> <span>strncmp</span>(<span>$str1</span>, <span>$str2</span>, 5)."<br>"<span>;
</span><span> 9</span> <span>//输出</span><span>-1</span>
<span>10</span> 
<span>11</span> ?>

strcmp(str1, str2)函数按照字符比较两个字符串，即两个字符串自左向右逐个字符比较（按ASCII值大小相比较），直到出现不同的字符或遇'