Usage of php substr() function

This article mainly introduces the description and usage ofsubstr()function parametersin php, and deeply analyzes the meaning of each parameter in the substr() function in the form of examples, and Examples illustrate its corresponding usage. Friends in need can refer to the following

The example in this article describes the parameter description and usage of the substr() function in PHP. Share it with everyone for your reference. The details are as follows:

stringsubstr(string $string, int $start [, int $length]), which can be used in a longerstringFind matching strings or characters in, $string is the string to be processed, $start is the position to start selecting, $length is the length to be selected.

$length is positive data and is read from left to right Get characters. When

$length is a negative number, read characters from right to left.

string Required, stipulates that a part of the string should be returned.

start Required, stipulates Where to start in the string.

charlist Optional, specifies the length of the string to be returned, the default is until the end of the string.

Positive number - starts at the specified position in the string

Negative numbers - start at the specified position from the end of the string

0 - start at the first character in the string

PHP Example CodeAs follows:

The code is as follows:

$rest_1 = substr("abcdef", 2); // returns "cdef" $rest_2 = substr("abcdef", -2); // returns "ef" $rest1 = substr("abcdef", 0, 0); // returns "" $rest2 = substr("abcdef", 0, 2); // returns "ab" $rest3 = substr("abcdef", 0, -1); // returns "abcde" $rest4 = substr("abcdef", 2,0); // returns "" $rest5 = substr("abcdef", 2,2); // returns "cd" $rest6 = substr("abcdef", 2, -1); // returns "cde" $rest7 = substr("abcdef", -2,0); // returns "" $rest8 = substr("abcdef", -2,2); // returns "ef" $rest9 = substr("abcdef", -2,-1); // returns "e"

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