ZEND PHP 5 Certification STUDY GUIDE

82 ” Strings And Patterns
echo str_replace("World", "Reader", "Hello World");
echo str_ireplace("world", "Reader", "Hello World");
In both cases, the function takes three parameters: a needle, a replacement string
and a haystack. PHP will attempt to look for the needle in the haystack (using either
a case-sensitive or case-insensitive search algorithm) and substitute every single instance
of the latter with the replacement string. Optionally, you can specify a third
parameter, passed by reference, that the function fills, upon return, with the number
of substitutions made:
$a = 0; // Initialize
str_replace (’a’, ’b’, ’a1a1a1’, $a);
echo $a; // outputs 3
If you need to search and replace more than one needle at a time, you can pass the
first two arguments to str_replace() in the form of arrays:
echo str_replace(array("Hello", "World"), array("Bonjour", "Monde"), "Hello
World");
echo str_replace(array("Hello", "World"), "Bye", "Hello World");
In the first example, the replacements are made based on array indexes—the first
element of the search array is replaced by the first element of the replacement array,
and the output is “Bonjour Monde”. In the second example, only the needle
argument is an array; in this case, both search terms are replaced by the same string
resulting in “Bye Bye”.
If you need to replace a portion of a needle of which you already know the starting
and ending point, you can use substr_replace():
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
echo substr_replace("Hello World", "Reader", 6);
echo substr_replace("Canned tomatoes are good", "potatoes", 7, 8);