如何检查字符串是否以指定的字符串开头? [英] How to check if a string starts with a specified string?

问题描述

我正在尝试检查字符串是否以http开头.我该如何检查?

I'm trying to check if a string starts with http. How can I do this check?

$string1 = 'google.com';
$string2 = 'http://www.google.com';

推荐答案

使用 substr 函数返回一个字符串的一部分.

Use the substr function to return a part of a string.

substr( $string_n, 0, 4 ) === "http"

如果您要确保它不是另一个协议.我会改用http://，因为https也会匹配，以及其他诸如http-protocol.com之类的东西.

If you're trying to make sure it's not another protocol. I'd use http:// instead, since https would also match, and other things such as http-protocol.com.

substr( $string_n, 0, 7 ) === "http://"

一般来说:

substr($string, 0, strlen($query)) === $query

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