CODEWITHSUNDEEP
javascriptjquerystring
SalmanShariati
SalmanShariati

Reputation: 3893

What is the easiest way to find out character repetition in a string using JS?

I have a string consist of 7 digits, I need a function that returns "true" if the string created by repetition of just 2 digits, something like : 

check('9669669');  // true
check('0000001');  // true
check('5555555');  // false
check('1111123');  // false

I want to know the easiest way. thanks.

Upvotes: 0

Views: 151

Answers (2)

kennebec
kennebec

Reputation: 104780

You can replace the first character globally, twice.

function check2(str){
    var fun= function(s){
        return s.replace(RegExp(s.charAt(0), 'g'), '')
    };
    str= fun(str);
    return !!(str && fun(str)=== '');
}

var A= ['9669669', '0000001', '5555555', '1111123'];

A.map(check2);

/* returned value: (Array) [true,true,false,false] */

Upvotes: 2

adeneo
adeneo

Reputation: 318202

Something like this should work, pushing unique characters in an array, and checking if it's length is 2

function check(str) {
    var arr = [], i = 0, parts = str.split('');

    for (var j=0; j<parts.length; j++) {
        if (arr.indexOf(parts[j]) === -1) arr.push(parts[j]);
    }

    return arr.length === 2;
}

FIDDLE

or more fancy

function check(str) {
    return str.split('').reduce(function(p, c) {
        if (p.indexOf(c) < 0) p.push(c); return p;
    }, []).length === 2;
}

Upvotes: 2

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