CODEWITHSUNDEEP
javascriptregexstring
Ivan
Ivan

Reputation: 13

If string matches regex replace, if not add variable

I'm using javascript to append a string to a variable (adding specific image size to a slider on mobile devices).

Here's the line I'm using.

var newsrc = src.substring(0, src.lastIndexOf(".")) + "-420x320" + src.substring(src.lastIndexOf("."));

However there are some cases where the image src has another size and in this case I would like to remove that size and add the one above.

Example: Both 

 http://domain.com/10001428289243jpg-700x703.jpg and
 http://domain.com/10001428289243jpg.jpg

Needs to be:

 http://domain.com/10001428289243jpg-420x320.jpg

What would you use in this case?

Upvotes: 0

Views: 76

Answers (3)

Paul
Paul

Reputation: 646

I'd stick in a quick replace that matches the -#x# pattern and replaces it with a blank.

var newsrc = src.replace(/(-\d+x\d+)/,"").substring(0, src.lastIndexOf(".")) + "-420x320" + src.substring(src.lastIndexOf("."));

Upvotes: 0

Rakesh_Kumar
Rakesh_Kumar

Reputation: 1442

FIDDLE LINK: http://jsfiddle.net/9u8m9oob/1/

You can achieve the same using below way also:

var str1='http://domain.com/10001428289243jpg.jpg';
var str2='http://domain.com/10001428289243jpg-700x703.jpg';
var regex=/^(http:\/\/domain\.com\/)(\d+jpg)(.)*(\.jpg)$/g;
var result= str1.replace(regex,"$1$2-420x320$4");
console.log(result);  // gives output as http://domain.com/10001428289243jpg-420x320.jpg

Upvotes: 0

Casimir et Hippolyte
Casimir et Hippolyte

Reputation: 89547

All you need is to build a pattern with an optional part:

src = src.replace(/(?:-\d+x\d+)?\.jpg$/, '-420x320.jpg');

where (?:-\d+x\d+)? is an optional non-capturing group and $ is an anchor for the end of the string.

Upvotes: 3

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