Removing

Lets image that we have an array

const myArray = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri'];  

and we want to remove "Wed" from this array.

Using the spread operator

There are no mutations with this code.

function removeItem(items, itemToRemove) { 
   const index = items.indexOf(itemToRemove); 
   return [. . . items.slice(0, index), . . .index.slice(index + 1)]; 
} 

Using the concat method

The concat method joins two arrays and puts them into a single flat array.

function removeItem(items, itemToRemove) { 
   const index = items.indexOf(itemToRemove); 
   return items.slice(0, index).concat(index.slice(index + 1)); 
} 

Using the splice method

The splice method can remove an item from an array.
This example will mutate the original array.

function removeItem(items, itemToRemove) { 
   const index = items.indexOf(itemToRemove); 
   items.splice(index,1); 
   return items; 
} 

Using a for loop

This uses a for loop and constructs a new array containing everything you want to keep.

function removeItem(items, itemToRemove) { 
   const newArray = []; 
   for (let I = 0; I < items.length; i++) { 
      if (items[i] !== itemToRemove) { 
        newArray.push(items[i]); 
      } 
   } 
   return newArray; 
}