Loop to remove an element in array with multiple occurrences

Question

I want to remove an element in an array with multiple occurrences with a function.

var array=["hello","hello","world",1,"world"];  function removeItem(item){     for(i in array){         if(array[i]==item) array.splice(i,1);     } } 

removeItem("world"); //Return hello,hello,1 

removeItem("hello"); //Return hello,world,1,world 

This loop doesn't remove the element when it repeats twice in sequence, only removes one of them.

Why?

Answer 1

You have a built in function called filter that filters an array based on a predicate (a condition).

It doesn't alter the original array but returns a new filtered one.

var array=["hello","hello","world",1,"world"]; var filtered = array.filter(function(element) {     return element !== "hello"; }); // filtered contains no occurrences of hello 

You can extract it to a function:

function without(array, what){     return array.filter(function(element){          return element !== what;     }); } 

However, the original filter seems expressive enough.

Here is a link to its documentation

Your original function has a few issues:

• It iterates the array using a for... in loop which has no guarantee on the iteration order. Also, don't use it to iterate through arrays - prefer a normal for... loop or a .forEach
• You're iterating an array with an off-by-one error so you're skipping on the next item since you're both removing the element and progressing the array.