CODEWITHSUNDEEP
javascriptregex
learning_programming
learning_programming

Reputation: 35

Regex for including only numbers and 2 special characters with space only

I am preparing a regular expression validation for text box where person can enter only 0-9,*,# each with comma seprated and non repeative. I prepared this

if( ( incoming.GET_DTMF_RESPONSE.value.match(/[0-9*#]\d*$/)==null ) )
alert("DTMF WRONG"

where incoming is functions back and GET_DTMF_RESPONSE is textbox name

I am not good in Regex..it is accepting 0-9 and * and # thats good but it is accepting a-z also i want it to make non repeative numbers and no alphabet and no special character excepting #,*

Let me know how to do this

Upvotes: 0

Views: 3584

Answers (2)

Anirudha
Anirudha

Reputation: 32797

How about this regex

^(?!.*,$|.*\d{2,})(?:([\d*#]),?(?!.*\1))+$

For each value separated by comma am capturing it into group1 and then am checking if it occurs ahead using \1(backreference)

^ marks the beginning of string

(?!.*,$|.*\d{2,}) is a lookahead which would match further only if the string doesn't end with , or has two or more digits

In (?:([\d*#]),?(?!.*\1))+ a single [\d*#] is captured in group 1 and then we check whether there is any occurrence of it ahead in the string using (?!.*\1). \1 refers to the value in group 1.This process is repeated for each such value using +

$ marks the end of string

For example

for Input

 1,2,4,6,2

(?!.*,$|.*\d{2,}) checks if the string doesn't end with , or has two or more digits

The above lookahead only checks for the pattern but doesn't match anything.So we are still at the beginning of string

([\d*#]) captures 1 in group 1

(?!.*\1) checks(not match) for 1 anywhere ahead.Since we don't find one,we move forward

Due to + we would again do the same thing

([\d*#]) would now capture 2 in group 1

(?!.*\1) checks(not match) for 2 anywhere ahead.Since we find it,we have failed matching the text

works here

But you better use non regex solution as it would be more simple and maintainable..

var str="1,2,4,6,6";
str=str.replace(/,/g,"");//replace all , with empty string
var valid=true;
for(var i=0;i<str.length-1;i++)
{
    var temp=str.substr(i+1);
    if(temp.indexOf(str[i])!=-1)valid=false;
}
//valid is true or false depending on input

Upvotes: 5

Casimir et Hippolyte
Casimir et Hippolyte

Reputation: 89557

You can use this:

^(?:([0-9#*])(?!(?:,.)*,\1)(?:,|$))+$

Upvotes: 0

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