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HomeBackend DevelopmentPHP TutorialPHP的substr_replace将指定两位置之间的字符替换为*号_PHP

复制代码 代码如下:
$username = "zongzi";
echo substr_replace($username,'**','1','2');

定义和用法

substr_replace() 函数把字符串的一部分替换为另一个字符串。

语法

substr_replace(string,replacement,start,length)
参数 描述
string 必需。规定要检查的字符串。
replacement 必需。规定要插入的字符串。
start

必需。规定在字符串的何处开始替换。

  • 正数 - 在第 start 个偏移量开始替换
  • 负数 - 在从字符串结尾的第 start 个偏移量开始替换
  • 0 - 在字符串中的第一个字符处开始替换
charlist

可选。规定要替换多少个字符。

  • 正数 - 被替换的字符串长度
  • 负数 - 从字符串末端开始的被替换字符数
  • 0 - 插入而非替换

提示和注释

注释:如果 start 是负数且 length 小于等于 start,则 length 为 0。
例子
复制代码 代码如下:
echo substr_replace("Hello world","earth",6);
?>

输出:
Hello earth

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