reegx-and -loop

JavaScript performance comparison

Test case created by pranavcbalan

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
loop
function check(str){
  if(!(str.length && str.length - 1)) return false;
  let temp = '';
  for(let i = 0;i<=str.length/2;i++){
    temp += str[i] 
    //console.log(str.replace(new RegExp(temp,"g"),''))
    if(!str.replace(new RegExp(temp,"g"),'')) return true;
  }
  return false;
}

console.log(check('aa')) //true
console.log(check('aaa')) //true 
console.log(check('abcabcabc')) //true
console.log(check('aba')) //false
console.log(check('ababa')) //false
pending…
regex
function check(str) {
  return /^(.+)\1+$/.test(str)
}


console.log(check('aa')) //true
console.log(check('aaa')) //true 
console.log(check('abcabcabc')) //true
console.log(check('aba')) //false
console.log(check('ababa')) //false
pending…
recursive
function check(str)
{
  if( str.length==1 ) return true; // trivial case
  for( var i=1;i<=str.length/2;i++ ) { // biggest possible repeated pattern has length/2 characters

    var p = str.substring(0, i);
    if( isRepeating(p,str) ) return true;
  }
  return false;
}


function isRepeating(p, str)
{
  if( str.length>p.length ) { // maybe more than 2 occurences

    var left = str.substring(0,p.length);
    var right = str.substring(p.length, str.length);
    return isRepeating(p,left) && isRepeating(p,right);
  }
  else if( str.length==p.length ) {
    if( str===p ) return true;
  }
  return false;
}

console.log(check('aa')) //true
console.log(check('aaa')) //true 
console.log(check('abcabcabc')) //true
console.log(check('aba')) //false
console.log(check('ababa')) //false
pending…
z function
function check(s) {
  var n = s.length;
  var z = Array(n).fill(0);
  var i, l, r;
  for (i = 1, l = 0, r = 0; i < n; ++i) {
    if (i <= r)
      z[i] = Math.min(r - i + 1, z[i - l]);
    while (i + z[i] < n && s[z[i]] == s[i + z[i]])
      ++z[i];
    if (i + z[i] - 1 > r)
      l = i, r = i + z[i] - 1;
  }
  return z.some(( v,i) => (i + v) === n && n % i === 0)
}
console.log(check('aa')) //true
console.log(check('aaa')) //true
console.log(check('abcabcabc')) //true
console.log(check('aba')) //false
console.log(check('ababa')) //false
pending…

Compare results of other browsers

Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL.

0 Comments