trim1 vs trim2 vs trim3

Edit on GitHub

Setup

function trim0(str) { return str.replace(/^(\s*)/, '').replace(/\s*$/, ''); }
  function trim1(str) { return str.replace(/^\s\s*/, '').replace(/\s\s*$/, ''); }
  function trim2(str) { return str.replace(/^\s+/, '').replace(/\s+$/, ''); }
  function trim3(str) { return str.substring(Math.max(str.search(/\S/), 0), str.search(/\S\s*$/) + 1); }
  function trim4(str) { return str.replace(/^\s+|\s+$/g, ''); }
  function trim5(s) {
  	var str = s.match(/\S+(?:\s+\S+)*/);
  	return str ? str[0] : '';
  }
  function trim6(str) { return str.replace(/^\s*(\S*(\s+\S+)*)\s*$/, '$1'); }
  function trim7(str) { return str.replace(/^\s*(\S*(?:\s+\S+)*)\s*$/, '$1'); }
  function trim8(str) { return str.replace(/^\s*((?:[\S\s]*\S)?)\s*$/, '$1'); }
  function trim9(str) { return str.replace(/^\s*([\S\s]*?)\s*$/, '$1'); }
  
  var trim10_whitespace = ' \n\r\t\f\x0b\xa0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000';
  function trim10(s) {
  	var str = s;
  	for (var i = 0; i < str.length; i++) {
  		if (trim10_whitespace.indexOf(str.charAt(i)) === -1) {
  			str = str.substring(i);
  			break;
  		}
  	}
  	for (i = str.length - 1; i >= 0; i--) {
  		if (trim10_whitespace.indexOf(str.charAt(i)) === -1) {
  			str = str.substring(0, i + 1);
  			break;
  		}
  	}
  	return trim10_whitespace.indexOf(str.charAt(0)) === -1 ? str : '';
  }
  function trim11(s) {
  	var str = s.replace(/^\s+/, '');
  	for (var i = str.length - 1; i >= 0; i--) {
  		if (/\S/.test(str.charAt(i))) {
  			str = str.substring(0, i + 1);
  			break;
  		}
  	}
  	return str;
  }
  function trim12(s) {
  	var	str = s.replace(/^\s\s*/, ""),
  		ws = /\s/,
  		i = str.length;
  	while (ws.test(str.charAt(--i)));
  	return str.slice(0, i + 1);
  }
  // trim12 with \s+ insteas od \s\s*
  function trim13(s) {
  	var	str = s.replace(/^\s+/, ""),
  		ws = /\s/,
  		i = str.length;
  	while (ws.test(str.charAt(--i)));
  	return str.slice(0, i + 1);
  }
  // trim12 without single ws=/\s/
  function trim14(s) {
  	var	str = s.replace(/^\s\s*/, ""),
  		i = str.length;
  	while (/\s/.test(str.charAt(--i)));
  	return str.slice(0, i + 1);
  }
  
  // same as trim11, but > not >=
  // buggy for "a " in Chromium
  function trim15(str) {
  	str = str.replace(/^\s+/, '');
  	for (var i = str.length - 1; i > 0; i--) {
  		if (/\S/.test(str.charAt(i))) {
  			str = str.substring(0, i + 1);
  			break;
  		}
  	}
  	return str;
  }
  trim15.buggy = true;
  
  // trim12 on http://zanstra.com/base/blog/trim_mac_roundup
  var trim16_whitespace = ' \n\r\t\v\f\u00a0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000';
  function trim16(s) {
  	var i = 0, j = s.length-1;
  	while(i < s.length && trim16_whitespace.indexOf(s.charAt(i)) != -1)
  		i++;
  	while(j > i && trim16_whitespace.indexOf(s.charAt(j)) != -1)
  		j--;
  	return s.substring(i,j+1);
  }
  
  // trim12 in http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-13585
  // looks to be buggy in Opera and Chromium. Works ok in Epiphany.
  // buggy for " ala ma " in Chromium
  // buggy for "ala ma " in Chromium
  function trim17(str) {
  	var str1 = str.replace(/^\s\s*/, '');
  	var len = str1.length;
  	if (len && /\s/.test(str1.charAt(len-1))) {
  		var re = /.*\S/g;
  		re.test(str1);
  		str1 = str1.slice(0, re.lastIndex);
  	}
  	return str1;
  }
  trim17.buggy=true;
  
  // trim in http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-39371
  // slightly changed return
  //var trim18_whitespace = trim21_whitespace;
  function trim18(str) {
  	var len = str.length;
  	if (len) {
  		while (trim21_whitespace[str.charCodeAt(--len)]);
  		if (++len) {
  			var i = 0;
  			while (trim21_whitespace[str.charCodeAt(i)]) {
  				++i;
  			}
  		}
  		return str.substring(i, len);
  	}
  	return str;
  }
  
  // http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-21439
  function trim19 (str) {
  	var ws = /\s/, _start = 0, end = str.length;
  	while(ws.test(str.charAt(_start++)));
  	while(ws.test(str.charAt(--end)));
  	return str.slice(_start - 1, end + 1);
  }
  
  // http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-28776
  function trim20(str) {
  	var whitespace = " \n\r\t\f";
  	for (var i = 0; i < str.length; i++)
  		if (whitespace.indexOf(str.charAt(i)) < 0)
  			break;
  
  	for (var j = str.length - 1; j >= i; j-- )
  		if (whitespace.indexOf(str.charAt(j)) < 0)
  			break;
  
  	return str.substring(i, j+1);
  }
  
  // in original it was manually populated, but looping is nicer
  var trim21_whitespace = {};
  var trim21_ww = [
  	0x0009,0x000a,0x000b,0x000c,0x000d,0x0020,0x0085,0x00a0,0x1680,0x180e,0x2000,0x2001,0x2002,0x2003,0x2004,0x2005,
  	0x2006,0x2007,0x2008,0x2009,0x200a,0x200b,0x2028,0x2029,0x202f,0x205f,0x3000
  ];
  for (var i = 0; i < trim21_ww.length; i++) {
  	trim21_whitespace[trim21_ww[i]] = true;
  }
  // http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-25052
  // looks to be buggy as it returns different results than others in Epiphany, Chromium (correct in Opera)
  // bug for "  a"
  // buggy for  ' 40. To no one will we sell.'  in Chromium
  function trim21(str) {
  	var n = str.length;
  	var s = trim21_whitespace;
  	var i;
  	if (!n) return str;
  	if (n && s[str.charCodeAt(n-1)]) {
  		do {
  			--n;
  		} while (n && s[str.charCodeAt(n-1)]);
  		if (n && s[str.charCodeAt(0)]) {
  			i = 1;
  			while (i < n && s[str.charCodeAt(i)])
  				++i;
  		}
  		return str.substring(i, n);
  	}
  	if (n && s[str.charCodeAt(0)]) {
  		i = 1;
  		while (i < n && s[str.charAt(i)])
  			++i;
  		return str.substring(i, n);
  	}
  	return str;
  };
  trim21.buggy=true;
  
  // rialto framework, http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-25038
  // VERY looks to be buggy as it returns different results than others in Epiphany, Chromium, Opera (in Opera even differently)
  // bug for " ", ' 40. To no one. ', '40. To no one. '
  function trim22(str) {
  	return str.replace(/^\s*(\b.*\b|)\s*$/, '$1');
  }
  trim22.buggy=true;
  
  // http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-13585
  // slightly moded return
  // looks to be buggy in Chromium (correct in Opera and Epiphany)
  // buggy for " ala ma " in Chromium
  // buggy for "ala ma " in Chromium
  function trim23(s) {
  	var str = s.replace(/^\s\s*/, ''),
  	len = str.length;
  	if (len && /\s/.test(str.charAt(len-1))) {
  		var re = /.*\S/g;
  		re.test(str);
  		return str.slice(0, re.lastIndex);
  	} else {
  		return str;
  	}
  }
  trim23.buggy=true;
  
  // http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-6808
  this.trim24 = (function(){
      var ws = {},
          chars = ' \n\r\t\v\f\u00a0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000';
      for(var i = 0; i < chars.length; i++ )
          ws[chars.charAt(i)] = true;
  
      return function( str ){
          var s = -1,
              e = str.length;
          while( ws[str.charAt(--e)] );
          while( s++ !== e && ws[str.charAt(s)] );
          return str.substring( s, e+1 );
      };
  })();
  
  // http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-6169
  function trim25(s) {
  	var str = s.replace(/^\s+/, '');
  	for (var i = str.length; i--;)
  		if (/\S/.test(str.charAt(i)))
  			return str.substring(0, ++i)
  	return str
  }
  
  // bug for "  s"
  function trim26(str) {
  	return str.replace(/^\s*(\S.*\S)?\s*$/, '$1');
  }
  trim26.buggy=true;
  
  
  
  var inp = "    \n\n \n\n   a \n a\n  a\n    a\n   a  \n\t\ta\t\ta\njahsdkjahkjshdakjhsdkahskd akhsjdh akjshd kashdkajhsd kajshd \nkauyiuqhwep iasldk qpwoie ad  \n   askdjaslkdjaslkjdaoiur qowioqwhr aspodiquw ijasod iqwiue pqowipoqiw epoqiwpeo iaslkjdqur \t kjahsdkj hakshd\nkajhdk\nk as d  \t\n".split('\n');
  
  function e(f) {
     var x = [];
     for (i = 0; i < inp.length; i++) {
       x.push(f(inp[i]));
     }
     return x;
  }

Tests

  • trim1

    e(trim1)
  • trim2

    e(trim2)
  • trim3

    e(trim3)