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Php 如何替换字符串的前三个字符_Php_Regex - Fatal编程技术网

Php 如何替换字符串的前三个字符

Php 如何替换字符串的前三个字符,php,regex,Php,Regex,如何替换字符串中的前三个特殊字符。? 这是样品 $string = "~~MASTER FOR OILCHEM; ETD - MID OF JUNE~~"; echo preg_replace("/[^a-zA-Z0-9]/", "", $string); 结果将是: MASTERFOROILCHEMETDMIDOFJUNE MASTER FOR OILCHEM; ETD - MID OF JUNE~~ 但我想替换前三个特殊字符。因此,输出将是: MASTERFOROILCHEMETDM

如何替换字符串中的前三个特殊字符。? 这是样品

$string = "~~MASTER FOR OILCHEM; ETD - MID OF JUNE~~";
 echo preg_replace("/[^a-zA-Z0-9]/", "", $string);
结果将是:

MASTERFOROILCHEMETDMIDOFJUNE
MASTER FOR OILCHEM; ETD - MID OF JUNE~~
但我想替换前三个特殊字符。因此,输出将是:

MASTERFOROILCHEMETDMIDOFJUNE
MASTER FOR OILCHEM; ETD - MID OF JUNE~~

您可以简单地使用
substr
来代替
regex

$string = "~~MASTER FOR OILCHEM; ETD - MID OF JUNE~~";
echo substr($string,2);

以下代码搜索0到3个非单词字符,并将其替换为空字符串:

$string = "~~MASTER FOR OILCHEM; ETD - MID OF JUNE~~";
echo preg_replace("/^\W{0,3}/", "", $string);
上述PHP输出以下内容:

MASTER FOR OILCHEM; ETD - MID OF JUNE~~
请参阅以获取一个实际示例

关于正则表达式,您应该试试这个很棒的工具。

子字符串($string,2)如何;同意你的意见+这是我的荣幸。