split strings with spaces

idxOf.js

function idxOf(str) {
  var results = [];
  var idx = str.indexOf(' ');

  while (idx >= 0 && str.length) {
    if (idx > 0) {
      results.push(str.slice(0, idx));
    }
    str = str.slice(idx + 1);
    idx = str.indexOf(' ');
  }

  if (str.length) {
    results.push(str);
  }

  return results;
}

var str = "     hoge   fuga aaaa にほんごーーーーー あああああ ??";

console.log(idxOf(str))

recursive.js

function recursive(str) {
  var idx = str.indexOf(' ');
  if (idx < 0) {
    return (str) ? [str] : [];
  }
  else if (idx == 0) {
    return recursive(str.slice(idx + 1));
  }

  return [str.slice(0, idx)].concat(recursive(str.slice(idx + 1)));
}


var str = "     hoge   fuga aaaa にほんごーーーーー あああああ ??  ";
console.log(recursive(str))

regexp2

function reg2(str) {
  var regex = new RegExp('([^ ]+) ?', 'g'),
     results = [],
     result;

  while (result = regex.exec(str)) {
    results.push(result[1]);
  }
  return results;
}

var str = "     hoge   fuga aaaa にほんごーーーーー あああああ ??  ";
console.log(reg2(str))

splitstr.js

var str = "h oge fuga yeah   commF031 fasd93+++. 日本語もいけちゃう ？ s  ";

function srch(str) {
  // search
  var curchars = [];
  var res = [];

  for (var i=0, l=str.length; i<l; i++) {
    var ch = str.charAt(i);
    if (ch == ' ') {
      if (curchars.length) {
        res.push(curchars.join(''));
        curchars = [];
      }
    }
    else {
      curchars.push(ch);
    }
  }
  if (curchars.length) {
    res.push(curchars.join(''));
  }

  return res;
}

function automaton(str) {
  const START     = 0;
  const NOT_EMPTY = 1;
  const END       = 2;

  var l = str.length;
  var state = START;
  var results = [];
  var current = '';

  var i = 0;

  while (state != END) {
    state = transition(state, i++);
  }

  return results;

  function transition(state, i) {
    if (i >= str.length) {
      if (state == NOT_EMPTY) {
        results.push(current);
      }
      return END;
    }
    var ch = str.charAt(i);
    var isSpace = ch == ' ';

    switch (state) {
      case START:
        if (isSpace) return START;
        current += ch;
        return NOT_EMPTY;

      case NOT_EMPTY:
        if (isSpace) {
          results.push(current);
          current = '';
          return START;
        }
        current += ch;
        return NOT_EMPTY;
      case END:
        return END;
    }
  }
}

function spl(str) {
  // split
  return str.trim().split(/ +/)
}


function reg(str) {
  // regexp
  return str.match(/[^ ]+/g) || [];
}

console.log(srch(str))
console.log(automaton(str))
console.log(spl(str))
console.log(reg(str))