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Last updated: Tue, 19 Sep 2006


(PHP 4, PHP 5)

substr_replace -- Replace text within a portion of a string


mixed substr_replace ( mixed string, string replacement, int start [, int length] )

substr_replace() replaces a copy of string delimited by the start and (optionally) length parameters with the string given in replacement. The result string is returned. If string is an array then array is returned.

If start is positive, the replacing will begin at the start'th offset into string.

If start is negative, the replacing will begin at the start'th character from the end of string.

If length is given and is positive, it represents the length of the portion of string which is to be replaced. If it is negative, it represents the number of characters from the end of string at which to stop replacing. If it is not given, then it will default to strlen( string ); i.e. end the replacing at the end of string.

Example 1. substr_replace() example

echo "Original: $var<hr />\n";

/* These two examples replace all of $var with 'bob'. */
echo substr_replace($var, 'bob', 0) . "<br />\n";
echo substr_replace($var, 'bob', 0, strlen($var)) . "<br />\n";

/* Insert 'bob' right at the beginning of $var. */
echo substr_replace($var, 'bob', 0, 0) . "<br />\n";

/* These next two replace 'MNRPQR' in $var with 'bob'. */
echo substr_replace($var, 'bob', 10, -1) . "<br />\n";
echo substr_replace($var, 'bob', -7, -1) . "<br />\n";

/* Delete 'MNRPQR' from $var. */
echo substr_replace($var, '', 10, -1) . "<br />\n";

Note: This function is binary-safe.

See also str_replace() and substr().

Last updated: Tue, 19 Sep 2006