Validating a pair of braces

braceValidate.js

var a = "{{{}}}}";
var ts = [];
var mismatch = false;
for (var i = 0; i < a.length; ++i) {
    if (a[i] === '{') {
        ts.push('{');
    }
    if (a[i] === '}') {
        if (ts.length == 0) {
            mismatch = true;
            break;

        }
        ts.pop('{');
    }
}

if (ts.length == 0 && !mismatch) {
    console.log('match');

} else {
    console.log('mismatch');
}