Question

My problem start with like-

var str='0|31|2|03|.....|4|2007'
str=str.replace(/[^|]\d*[^|]/,'5');

so the output becomes like:”0|5|2|03|….|4|2007″ so it replaces 31->5

But this doesn’t work for replacing other segments when i change code like this:

str=str.replace(/[^|]{2}\d*[^|]/,'6');

doesn’t change 2->6.
What actually i am missing here.Any help?

Answer 1

Here is a specific regex solution which replaces the number following the first | pipe symbol with the number 5:

var re = /^((?:\d+\|){1})\d+/;
return text.replace(re, '$15');

If you want to replace the digits following the third |, simply change the {1} portion of the regex to {3}

Here is a generalized function that will replace any given number slot (zero-based index), with a specified new number:

function replaceNthNumber(text, n, newnum) {
    var re = new RegExp("^((?:\\d+\\|){"+ n +'})\\d+');
    return text.replace(re, '$1'+ newnum);
}