JavaScript Forum

**Physicsguy** · 08-11-2009, 02:54 PM

Hi there,

I'm trying to make something that changes all 'hello's to 'goodbye's, and all 'dog's to 'cat's. Here's what I've got.

Code:

<script type="text/javascript">

var str="Hello there cat, and hi other dog. ";
document.write(str.replace(/Hello/g, "Goodbye"),(/dog/g, "cat"));


</script>

I want that above code to output "Goodbye there cat, and hi other cat.", but it outputs "Goodbye there cat, and hi other dog. cat"

Also this:

<script type="text/javascript">

var str="Hello there cat, and hi other dog. Hello also other dog!";
document.write(str.replace(/Hello/g, "Goodbye"),(/dog/g, "cat"));

</script>

Which should output "Goodbye there cat, and hi other cat. Goodbye also other cat!"

But it outputs "Goodbye there cat, and hi other dog. Goodbye also other dog!cat"

WHY DOES THIS NOT WORK?? I'm obviously not making it replace useless things like 'god' and 'cat', but other things. I made it simple so it's easier to understand.

**tripy** · 08-11-2009, 05:39 PM

Because you cannot chain several changes with replace(replace1, replace2)
Beside, look closely to your code, the "(/dog/g, "cat")" is a second parameter to document.write(), not str.replace()

document.write(str.replace(/Hello/g, "Goodbye"),(/dog/g, "cat"));

You have to work in 2 phases

Code:

var str="Hello there cat, and hi other dog. ";
str=str.replace(/Hello/g, "Goodbye");
str=str.replace(/dog/g, "cat");
document.write(str);

or, smaller

Code:

var str="Hello there cat, and hi other dog. ";
str=str.replace(/dog/g,str.replace(/Hello/g, "Goodbye"));
document.write(str);

**Physicsguy** · 08-11-2009, 08:28 PM

Quote:

Originally Posted by tripy

Because you cannot chain several changes with replace(replace1, replace2)
Beside, look closely to your code, the "(/dog/g, "cat")" is a second parameter to document.write(), not str.replace()

document.write(str.replace(/Hello/g, "Goodbye"),(/dog/g, "cat"));

You have to work in 2 phases

Code:

var str="Hello there cat, and hi other dog. ";
str=str.replace(/Hello/g, "Goodbye");
str=str.replace(/dog/g, "cat");
document.write(str);

or, smaller

Code:

var str="Hello there cat, and hi other dog. ";
str=str.replace(/dog/g,str.replace(/Hello/g, "Goodbye"));
document.write(str);

THANK YOU! The first one works like a charm, but the second one doesn't work... But I'm using the first one, thank you!

If you would like I can give you credit for this in the credits for the webapp I'm working on.

**Physicsguy** · 08:57 PM

OK, That works, and I've done something with it, but here's what I have now in my entire page so far:

Code:

<html>
<body>
<?php echo"
<script type='text/javascript'>

var str='$userinput';
str=str.replace(/12345/gi, '67890'); //Replaces '12345' with '67890'// 
str=str.replace(/if/gi, 'if (');
str=str.replace(/less than/gi, '<');
str=str.replace(/write/gi, 'document.write(\"');

function outputcode()
{
document.write(str);
}

</script>


<INPUT TYPE=\"text\" SIZE='25' NAME=\"site\" value=\"$userinput\" />
<input type=\"button\" name=\"submitbutton\" value=\"Submit\" onclick=\"outputcode()\"/>

";?>
</body>
</html>

Why doesn't this work? I have a feeling I'm missing something HUGE here but I'm too stupid to see it. Once you mix JS with PHP I just get messed up...

BTW sorry for double-post

:O

And for the example above, try just typing in the box '12345'. Looking at the code, it should replace '12345' with '67890' but nothing happens...