(PHP 4, PHP 5)
substr_replace — Replace text within a portion of a string
substr_replace() replaces a copy of
string
delimited by the
start
and (optionally)
length
parameters with the string given in
replacement
.
string
The input string.
An array of strings can be provided, in which
case the replacements will occur on each string in turn. In this case,
the replacement
, start
and length
parameters may be provided either as
scalar values to be applied to each input string in turn, or as
arrays, in which case the corresponding array element will
be used for each input string.
replacement
The replacement string.
start
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
.
length
If 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
. Of course, if
length
is zero then this function will have the
effect of inserting replacement
into
string
at the given
start
offset.
The result string is returned. If string
is an
array then array is returned.
Example #1 Simple substr_replace() examples
<?php
$var = 'ABCDEFGH:/MNRPQR/';
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";
?>
Example #2 Using substr_replace() to replace multiple strings at once
<?php
$input = array('A: XXX', 'B: XXX', 'C: XXX');
// A simple case: replace XXX in each string with YYY.
echo implode('; ', substr_replace($input, 'YYY', 3, 3))."\n";
// A more complicated case where each replacement is different.
$replace = array('AAA', 'BBB', 'CCC');
echo implode('; ', substr_replace($input, $replace, 3, 3))."\n";
// Replace a different number of characters each time.
$length = array(1, 2, 3);
echo implode('; ', substr_replace($input, $replace, 3, $length))."\n";
?>
The above example will output:
A: YYY; B: YYY; C: YYY A: AAA; B: BBB; C: CCC A: AAAXX; B: BBBX; C: CCC
Note: This function is binary-safe.