CODEWITHSUNDEEP
javascriptif-statement
Nicholas Tibbs
Nicholas Tibbs

Reputation: 170

JS - If statement with many conditions

My goal was to determine if an array contained any falsey elements and create a new array without those elements. I came up with a HORRIBLY ugly function but i just couldnt figure out a better way to write it.

    function bouncer(arr) {
  var newArray = [];
  for (var i = 0; i < arr.length; i++)
    if (arr[i] !== false ) {
      if (arr[i] !== NaN) {
        if (arr[i] !== "") {
          if (arr[i] !== 0) {
            if (arr[i] !== undefined) {
              if (arr[i] !== null) {
      newArray.push(arr[i]);
    }}}}}}
  return newArray;


}

bouncer([7, 'ate', '', false, 9]);

I tried using an if statement using miltiple conditions like 

if (arr[i] !== false || arr[i] !== "")

But when I did that it wouldnt catch both conditions for some reason. what would have been a simpler way to do this ?

Upvotes: 3

Views: 362

Answers (4)

Nina Scholz
Nina Scholz

Reputation: 386848

Check if arr[i] is truthy and then push the value.

arr[i] && newArray.push(arr[i]);

Complete code:

function bouncer(arr) {
    var newArray = [], i;
    for (i = 0; i < arr.length; i++) {
        arr[i] && newArray.push(arr[i]);
    }
    return newArray;
}

Or with Array.filter:

newArr = arr.filter(function (a) { return a; });

Upvotes: 1

Luke
Luke

Reputation: 5708

A more readable version of @Nina Scholz's answer would be to explicitly check for truthiness without relying on short circuiting.

if (arr[i]) { newArray.push(arr[i]); }

Of course for your situation, you could use filter

newArr = arr.filter(function(el){ return el == true; });

Upvotes: 1

kyldvs
kyldvs

Reputation: 61

You should use filter.

var arr1 = [0, 1, false, '', 'zero', null];
var arr2 = arr1.filter(function (item) {
  return !!item;
});
console.log(arr2); // [1, 'zero']

Documentation for filter can be found here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter

Upvotes: 0

taxicala
taxicala

Reputation: 21789

You are using OR, should use AND instead:

if (arr[i] !== false && arr[i] !== "")

Upvotes: 1

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