javascripts regular expression

Question

I have this string 1,2,3,4,5

and say i remove 1 then it becomes ,2,3,4,5 or 1,2,,4,5

how do I remove "1," or any number from the list and replace those extra commas and also keep in mind the last number "5" doesnt have a comma.

I can use the string replace javascript function , I am more concerned with the last number

example if i remove 5 it should show as 1,2,3,4

• jball: Wait - do you have a string or an array?
• jball: Looking at your comment on @webSol's answer, it sounds like you want a method to remove any given number from a comma-delimited string? If this is correct, please update your question accordingly. And clarify the whole "string or array" thing.
• tchrist: @jball: There is no comma-delimited string to be seen here. Consider :foo:bar:. That has 2 fields if colon-delimited, 3 fields if colon-terminated, and 4 fields if colon-separated. We're programmers: don't get sloppy.
• user244394: @jball that right its a string
• jball: @tchrist, what?! Ref: A delimiter is a sequence of one or more characters used to specify the boundary between separate, independent regions in plain text or other data streams, particularly field delimiters

Answer 1

theString.replace(/«the number»,?|,«the number»$/, '')

>>> "1,2,3,4,5".replace(/1,?|,1$/, '')
"2,3,4,5"
>>> "1,2,3,4,5".replace(/2,?|,2$/, '')
"1,3,4,5"
>>> "1,2,3,4,5".replace(/5,?|,5$/, '')
"1,2,3,4"

Or treat the string as an array, with

theString.split(/,/).filter(function(x){return x!="«the number»";}).join(",")

>>> "1,2,3,4,5".split(/,/).filter(function(x){return x!="1";}).join(",")
"2,3,4,5"
>>> "1,2,3,4,5".split(/,/).filter(function(x){return x!="2";}).join(",")
"1,3,4,5"
>>> "1,2,3,4,5".split(/,/).filter(function(x){return x!="5";}).join(",")
"1,2,3,4"

Answer 2

Don't use regular expression. Use arrays. You can split() your string into an array on the comma, then remove the elements as needed. You can then use join() to put them back together as a string.

• jball: +1 - though you should mention join to rebuild the string from the array
• user244394: var str = '1,2,3,4,5'; str = str.replace('1,', ''); I am trying to remove any of the numbers but this fails when you try to replace "5" str = str.replace('5,', '')
• jball: @user244394 str.replace is not mentioned in this answer, and you are providing conflicting specifications in your question and subsequent comments.
• user244394: I was trying couple thing split and replace

Answer 3

function removeValue(value, commaDelimitedString)
{
 var items = commaDelimitedString.split(/,/);
 var idx = items.indexOf(value);
 if(idx!=-1) { items.splice(idx, 1); }
 return items.join(",");
}

• Jason McCreary: +1 nice function. I guess not as pretty as KennyTM though ;)
• jball: @Jason McCreary, Thanks, though to be fair, I voted for KennyTM's as well :)

Answer 4

you can use split and merge functions in javascript