A function of replacing a part of a PHP string with another string Substr_replace ()

Instance

Replace "Hello" with "World":

<?phpecho substr_replace ("Hello", "World", 0);? >

Definition and usage

The Substr_replace () function replaces part of a string with another string.

Note: If the start parameter is negative and length is less than or equal to start, length is 0.

Note: This function is binary safe.

Grammar

Substr_replace (String,replacement,start,length)

Parameters	Describe
String	Necessary. Specifies the string to check.
Replacement	Necessary. Specifies the string to insert.
Start	Necessary. Specifies where the string begins to be replaced. Positive number-starts at the specified position in the string Negative number-starts at the specified position from the end of the string 0-Starts at the first character in a string
Length	Optional. Specifies the number of characters to replace. The default is the same length as the string. Positive number-The length of the string being replaced Negative-the number of characters to be replaced starting at the end of the string 0-Insert rather than replace

Technical details

return value:	returns the replaced string. If the string is an array, the array is returned.
php version:	4+
update log:	since PHP 4.3.3, all parameters accept arrays.

More examples

Example 1

Replace from the 6th position of the string (replace "World" with "Earth"):

<?phpecho substr_replace ("Hello World", "Earth", 6);? >

Example 2

Start with the 5th position at the end of the string (replace "World" with "Earth"):

<?phpecho substr_replace ("Hello World", "Earth",-5);? >

Example 3

Insert "Hello" at the beginning of "World":

<?phpecho Substr_replace ("World", "Hello", 0,0);? >

Example 4

Replace multiple strings at once. Replace "AAA" in each string with "BBB":

<?php$replace = Array ("1:AAA", "2:aaa", "3:aaa"), Echo implode ("<br>", Substr_replace ($replace, ' BBB ', 3, 3));? >

Example:

<?phpecho substr_replace (' abcdef ', ' # # # ', 1);//Output a## #echo substr_replace (' ABCdef ', ' # # # ', 1, 2);//Output a## #defecho substr_replace (' abcdef ', ' # # ',-3, 2);//Output abc## #fecho substr_replace (' abcdef ', ' # # # ', 1,-2);//output a## #ef;