replace single words in php

[e111982]

Hi. I have got a problem. I have a string like:

 

$old="apple";

$new="lemon";

 

$str="I have got one green apple, two yellow apples, oranges and grapes.";

 

I want an output as :

 

I have got one green lemon,two yellow apples, oranges and grapes.

 

However str_replace replaces all occurrences. I need only words to be replaced. Thanks.

[Andy-H]

Use preg_replace it allows you to add a limit to the replacement.

 

<?php
$old ="#apple#i";
$new ="lemon";

$str ="I have got one green apple, two yellow apples, oranges and grapes.";
$str = preg_replace($old, $new, $str, 1);

echo 'Output: ' . $str;
?>

 

Output: I have got one green lemon, two yellow apples, oranges and grapes.

 

[Alex]

You can use preg_replace to do this. Example:

 

$old="apple";
$new="lemon";
$str="I have got one green apple, two yellow apples, oranges and grapes.";
echo preg_replace("~\b$old\b~", $new, $str);

 

Edit: Angy-H's solution will only work if the occurrence of the string that you want to replace is the first one in the string.

[e111982]

thanks a lot. 

[Andy-H]

Can you explain what the word boundry is doing? I was looking into it and found this:

 

http://www.regular-expressions.info/wordboundaries.html

 

but it is confusing as hell....

 

EDIT:

 

NVM, just noticed that the second word is apples and not apple and it hit me, lol.

[Alex]

The word boundary, \b, just matches anything that might border a word. Ex: space, comma, period, etc..

[Andy-H]

So the boundary only matches on the condition that the boundary character matched is non-word charter?

[Alex]

Basically, here is some good reading on word boundaries in regex.

[e111982]

How can I make it case insensitive? For example:

 

$old="apple";

$new="lemon";

 

$str="I have got one green Apple, two yellow apples, oranges and grapes.";

 

echo preg_replace("~\b$old\b~", $new, $str);

 

returns:

 

I have got one green Apple, two yellow apples, oranges and grapes.

 

Is there a way for it to return :

 

I have got one green lemon, two yellow apples, oranges and grapes.

 

Thanks...

[Mchl]

~\b$old\b~i

[emopoops]

u could use array jews asl weel..

[Maq]

u could use array jews asl weel..

 

Huh...?

[emopoops]

im sorry i meant an array of keys as well.