using regex to replace a match in a string

Question

I'm trying to use String.replace() with a regular expression to replace a matched expression.

Like so:

var newStr = loc.replace(/Slide(\d*)/,(i+1));

This expression turns

https://xxxxxxx.net/qa/club/Slide1.PNG

into

https://xxxxxxx.net/qa/club/1.PNG

I just want to replace the numbers after "Slide", without removing the word. How can I do this?

dee-see · Accepted Answer · 2014-01-13 21:42:28Z

3

Use a capture group and insert it in your replacement.

loc.replace(/(Slide)\d*/, '$1' + (i+1));

If the word will always be slide, then you can simply use this without capturing anything

loc.replace(/Slide\d*/, 'Slide' + (i+1));

The paratheses around (i + 1) are important to force the mathematical operation before string concatenation.

If Slide is always followed by a number, change the * to a + in the regular expression.

answered Jan 13, 2014 at 21:35

dee-see

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1 Comment

I don't want Slide at all. I just want the number. The + seems to Match Slide in addition to the number.