php substr_replace替换字符串一些实例

substr_replace与str_replace有一点像就是直接把字符串替换一部份了，下面小编来给各位同学介绍一下 操作方法。

substr_replace() 函数把字符串的一部分替换为另一个字符串。

用法

substr_replace(string,replacement,start,length)

注意当字符串包含中文时，不经过特殊处理会出现乱码。

代码如下

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$string1="123456789"; echo substr_replace($string1,'###',0); //### echo substr_replace($string1,'###',5); //12345### echo substr_replace($string1,'###',0,0); //###123456789 echo substr_replace($string1,'###',8,-2); //12345678###9 echo substr_replace($string1,'###',-6,-1); //123###9 echo "n"; echo substr_replace($string1,'###',-1); //123###9 echo "n"; echo substr_replace($string1,'###',1,-1); //1###9 echo substr_replace($string1,'###',1,1); //1###3456789 ?>

例2

代码如下

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$var = 'ABCDEFGH:/MNRPQR/'; echo "Original: $var n"; /* These two examples replace all of $var with 'bob'. */ echo substr_replace($var, 'bob', 0) . " n"; echo substr_replace($var, 'bob', 0, strlen($var)) . " n"; /* Insert 'bob' right at the beginning of $var. */ echo substr_replace($var, 'bob', 0, 0) . " n"; /* These next two replace 'MNRPQR' in $var with 'bob'. */ echo substr_replace($var, 'bob', 10, -1) . " n"; echo substr_replace($var, 'bob', -7, -1) . " n"; /* Delete 'MNRPQR' from $var. */ echo substr_replace($var, '', 10, -1) . " n"; ?>

Original: ABCDEFGH:/MNRPQR/
bob
bob
bobABCDEFGH:/MNRPQR/
ABCDEFGH:/bob/
ABCDEFGH:/bob/
ABCDEFGH://

将过长的字符串用省略号代替一部分

下面的程序可以将过长的字符串保留首尾，中间用省略号代替。

代码如下	复制代码
$longString = 'abcdefghijklmnopqrstuvwxyz0123456789z.jpg'; $separator = '...'; $separatorlength = strlen($separator) ; // 需要保留的字符串 $maxlength = 25 - $separatorlength; // 从一半的长度开始 $start = $maxlength / 2 ; // 计算偏移量 $trunc = strlen($longString) - $maxlength; echo substr_replace($longString, $separator, $start, $trunc); //prints "abcdefghij...56789z.jpg" ?>

程序运行结果：

abcdefghijk...456789z.jpg

Program List：将多出的字符用省略号代替

代码如下

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function truncate($text,$numb) { $text = html_entity_decode($text, ENT_QUOTES); if (strlen($text) > $numb) { $text = substr($text, 0, $numb); $text = substr($text,0,strrpos($text," ")); //This strips the full stop: if ((substr($text, -1)) == ".") { $text = substr($text,0,(strrpos($text,"."))); } $etc = "..."; $text = $text.$etc; } $text = htmlentities($text, ENT_QUOTES); return $text; } //Call function $text = 'welcome to nowamagic, welcome to nowamagic, welcome to nowamagic'; $result = truncate($text, 35); echo $result; ?>

好了你大概会知道此函数的作用了。