CODEWITHSUNDEEP
javascriptarrays
user8492975
user8492975

Reputation:

Return 0 if there are no string in an array - JS

I have a function here that takes the smallest number in an array.

What I did is that I filtered out only numbers using typeof property and compared the values from Infinity.

Right now, it will return 0 if the array is empty.

However if the array contains only string or other datatypes it will return Infinity.

Here's my codes:

function findSmallestNumberAmongMixedElements(arr) {

  var smallestNum = Infinity;

  if(arr.length !== 0){
   for(var i = 0; i < arr.length; i++){
     if(typeof arr[i] === 'number' && arr[i] < smallestNum){
         smallestNum = arr[i];
     } 
   }
     return smallestNum;
  } 
  return 0;
}


var output = findSmallestNumberAmongMixedElements(['sam', 3, 2, 1]);
console.log(output); // --> 4

It must return 0 as well if there are no numbers in the array.

Any idea what am I doing wrong here?

Upvotes: 1

Views: 1866

Answers (4)

gidim
gidim

Reputation: 2323

There are probably some more elegant ways to solve this. but this fixes your bug.

function findSmallestNumberAmongMixedElements(arr) {

  var smallestNum = Infinity;
  var numberFound = false

   for(var i = 0; i < arr.length; i++){
     if(typeof arr[i] === 'number' && arr[i] < smallestNum){
         smallestNum = arr[i];
         numberFound = true
     } 
   }
    if(numberFound)
      return smallestNum;

  return 0;
}

Upvotes: 2

user663031
user663031

Reputation:

The problem is that you are special-casing the empty-array case, with the line 

if(arr.length !== 0){

Remove that. Then, if you want to force a result of Infinity to 0, do that at the end.

function findSmallestNumberAmongMixedElements(arr) {

  var smallestNum = Infinity;

  for(var i = 0; i < arr.length; i++){
    if(typeof arr[i] === 'number' && arr[i] < smallestNum){
       smallestNum = arr[i];
    } 
  }

  return isFinite(smallestNum) ? smallestNum : 0;
}

However, it is simpler to just filter out the non-numbers using filter, and calculate the minimum using Math.min. This also makes easier to fix a "bug" in the code above, which is that it will yield 0 for inputs such as [Infinity, "foo", Infinity]. I'm not sure whether you prefer to return 0 or Infinity in that kind of case. Assuming you do want to return 0, then

function findSmallestNumberAmongMixedElements(arr) {
  var nums = ...arr.filter(elt => typeof elt === 'number');

  return nums.length ? Math.min(...nums) : 0;
}

Upvotes: 0

Jaromanda X
Jaromanda X

Reputation: 1

You could use an odd way of using Array#reduce and Array#filter

First, filter out non-numeric

Second reduce this filtered array, with an initial value of 0 - if the array is zero length, reduce will return 0

function findSmallestNumberAmongMixedElements(arr) {
    var smallestNum = Infinity;
    return arr.filter(item => typeof item == 'number').reduce((min,item) => {
        if(item < smallestNum) smallestNum = item;
        return smallestNum;
    }, 0);
}
console.log(findSmallestNumberAmongMixedElements([]));
console.log(findSmallestNumberAmongMixedElements(['1','2','3']));
console.log(findSmallestNumberAmongMixedElements([1,2,3]));
console.log(findSmallestNumberAmongMixedElements(['1',2,3]));

Upvotes: -1

Engineer Passion
Engineer Passion

Reputation: 1181

function findSmallestNumberAmongMixedElements(arr) {

  var smallestNum = Infinity;

  if(arr.length !== 0){
   for(var i = 0; i < arr.length; i++){
     if(typeof arr[i] === 'number' && arr[i] < smallestNum){
         smallestNum = arr[i];
     } 
   }
     return smallestNum == Infinity? 0 : smallestNum; // if smallest doesn't change return 0
  } 
  return 0;
}


var output = findSmallestNumberAmongMixedElements(['sam', 3, 2, 1]);
console.log(output);

Upvotes: 0

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