CODEWITHSUNDEEP
javascriptfor-loop
swaggyP
swaggyP

Reputation: 365

displaying rest of contents of an array

I am trying to use a FOR loop to display contents of an array.

the function I want to create is similar to underscore.js _.rest function except the objective is touse a FOR loop.

rest(anyArray, n);

so if I were to enter "rest([1,2,3,4,5], 3);", I want to return "[4,5]".

Here is what I have and it does not work:

rest: function (anyArray, n) {
  var isArray = (anyArray instanceof Array),
    isNum = (typeof n === 'number'),
    result = new Array,
    valRange = (n >= 0);
  if (isArray && isNum) {
    for (len = anyArray.length, i = 0, j = (len - (n + len)); i < j, n < len; i++, j++) {
      result[i] = anyArray[j];
    }
    return result;
  }
}

Upvotes: 0

Views: 372

Answers (2)

Explosion Pills
Explosion Pills

Reputation: 191779

rest: function (anyArray, n) {
    return anyArray.slice(n);
}

rest: function (anyArray, n) {
    var output = [];
    for (; n < anyArray.length; n++) {
        output.push(anyArray[n]);
    }
    return output;
}

Upvotes: 1

Bergi
Bergi

Reputation: 664971

The part that leads to "not working" is j = (len - (n + len)): Essentially, you say j = n, and then you are looping while i < j. I'd expect that what you actually want is j < len. Also, you should add the var keyword:

rest: function(anyArray, n){
    var isArray = (anyArray instanceof Array),
        isNum = (typeof n === 'number'),
        result = [];
    if (isArray && isNum) {
        for (var len = anyArray.length, i = 0, j = n; j < len; i++, j++) {
            result[i] = anyArray[j];
        }
        return result;
    }
    // else?
}

Of course, just using the native slice method would be much easier.

Upvotes: 0

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