php man page for substr_replace

SUBSTR_REPLACE(3)							 1							 SUBSTR_REPLACE(3)

substr_replace - Replace text within a portion of a string

SYNOPSIS
       mixed substr_replace (mixed  $string, mixed  $replacement, mixed  $start, [mixed  $length])

DESCRIPTION
       substr_replace(3) replaces a copy of $string delimited by the $start and (optionally) $length parameters with the string given in $replace-
       ment.

PARAMETERS
	      o $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.

	      o $replacement
		- The replacement string.

	      o $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.

	      o $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 rep-
		resents 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.

RETURN VALUES
	The result string is returned. If $string is an array then array is returned.

EXAMPLES
       Example #1

	      Simple substr_replace(3) examples

	      <?php
	      $var = 'ABCDEFGH:/MNRPQR/';
	      echo "Original: $var<hr />
";

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

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

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

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

       Example #2

	       Using substr_replace(3) 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))."
";

	      // A more complicated case where each replacement is different.
	      $replace = array('AAA', 'BBB', 'CCC');
	      echo implode('; ', substr_replace($input, $replace, 3, 3))."
";

	      // Replace a different number of characters each time.
	      $length = array(1, 2, 3);
	      echo implode('; ', substr_replace($input, $replace, 3, $length))."
";
	      ?>

	      The above example will output:

	      A: YYY; B: YYY; C: YYY
	      A: AAA; B: BBB; C: CCC
	      A: AAAXX; B: BBBX; C: CCC

NOTES
       Note

	      This function is binary-safe.

SEE ALSO
       str_replace(3), substr(3), String access and modification by character.

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