Regex that matches integers only

Question

I\'m currently using the pattern: \\b\\d+\\b, testing it with these entries:

numb3r 
2
3454 
3.214
test

I only want it to catc

Answer 1

Similar to manojlds but includes the optional negative/positive numbers:

var regex = /^[-+]?\d+$/;

EDIT

If you don't want to allow zeros in the front (023 becomes invalid), you could write it this way:

var regex = /^[-+]?[1-9]\d*$/;

EDIT 2

As @DmitriyLezhnev pointed out, if you want to allow the number 0 to be valid by itself but still invalid when in front of other numbers (example: 0 is valid, but 023 is invalid). Then you could use

var regex = /^([+-]?[1-9]\d*|0)$/

Answer 2

Try /^(?:-?[1-9]\d*$)|(?:^0)$/.

It matches positive, negative numbers as well as zeros.

It doesn't match input like 00, -0, +0, -00, +00, 01.

Online testing available at http://rubular.com/r/FlnXVL6SOq

Answer 3

You could use lookaround instead if all you want to match is whitespace:

(?<=\s|^)\d+(?=\s|$)

Answer 4

This just allow positive integers.

^[0-9]*[1-9][0-9]*$