Filter Arrays with filter !==5

JavaScript
1

Tell us what’s happening:

Hello everyone,

I am trying to understand why it uses !==5 instead of just saying… val===5 … or is it just preference in this situation.

The following code is an example of using filter to remove array elements that are equal to five:

array = array.filter(function(val) {
  return val !== 5;
});

Thanks

Your code so far

var oldArray = [1,2,3,4,5,6,7,8,9,10];

// Only change code below this line.

var newArray = oldArray.filter(function(val){
  return val < 6;
});

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/604.5.6 (KHTML, like Gecko) Version/11.0.3 Safari/604.5.6.

Link to the challenge:
https://www.freecodecamp.org/challenges/filter-arrays-with-filter

2

.filter will remove any value that does not return true for the given condition.

so val !== 5 will remove 5 from the array as 5 !== 5 returns false

3

the code is saying…
filter the array and return any values that are not equal to 5?
you could do if val === 5 ( cut it from the array) and return the resulting array…
this way is faster mebbe?

5

To be pedantic, it removes any element that returns a falsy value (so returning 5, "foo", etc. is just as good as returning true):

[0, 5, "foo", null].filter(function(el) {
  return el;
}); // [5, "foo"]
6

Good point, I hadn’t thought of using filter like that. I’m sure I will find a problem to use it on!

Thanks :slightly_smiling_face: