How to remove the first digit from a php string

PHP language is a widely used server-side scripting language. It is favored by the industry for its high efficiency and ease of use. In PHP, operating strings is a very basic function, and removing the first digit of a string is also a very common operation. This article will introduce in detail how to perform this operation in PHP.

1. Use the substr function

The substr function is a function in PHP used to intercept strings. It can specify the position from which to intercept and the length of the interception.

Code example:

$str = "Hello World";
$str = substr($str, 1); // 去掉字符串的首位一位
echo $str; // 输出 "ello World"

In this example, we first assign a string to the variable $str, and then use the substr function to intercept it starting from the second character. Since the interception length is not specified, the substr function will automatically intercept to the end of the string.

Although this method is simple, it should be noted that the first parameter of the substr function is the string to be intercepted, and the second parameter is the position from which to intercept. If you want to remove the first bit of the string, you should pass 1 instead of 0 as the second parameter, because the index of the first character in the string is 0.

2. Use the preg_replace function

The preg_replace function is a function used for regular expression replacement in PHP. It can replace the part of the string that meets certain rules. We can use the preg_replace function to replace the first character of the string with an empty string to remove the first character.

Code example:

$str = "Hello World";
$str = preg_replace("/^.|.$/", "", $str); // 去掉字符串的首位一位
echo $str; // 输出 "ello Worl"

In this example, we first assign a string to the variable $str, and then use the preg_replace function to set its matching rule to match the beginning and end of the string. Delete one character at the end position to achieve the purpose of deleting the first character.

The advantage of this method is that it can handle multi-string matching well.

Summary

In PHP, removing the first digit of a string is a very basic operation, and it is also a skill we often use in string operations. Using the substr function and the preg_replace function are both feasible methods. The specific method to use depends on the actual needs and usage scenarios. No matter which method is used, you need to pay attention to the passing of parameters when using it to ensure that the required functions are achieved.

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