What is the proper way to remove an array value using the 'splice'

Question

What is the proper way to remove an array value using the 'splice'

Having trouble removing values from an array using splice. I tried using both delete and splice methods but neither seem to work as expected.

var arr = [];
 arr[2] = 22;
 arr[5] = 3;
 arr[99] = 3343;
 for(var i in arr){
    if(i != 2){
    arr.splice(i,1);
    }
   //delete arr[i];
 }
 console.log(arr);// [2: 22, 98: 3343]
 //wanted [2:22]

I am attempting to remove all elements from the array except the one at index 2, however it only deletes one element. Any suggestions on how to achieve this?

javascript arrays

Answer 1

Answer №1

There's no need for a for loop when using the splice method, you can simply use: arr.splice(0,arr.length)

If you just want to delete all elements, you can do so by doing arr=[].

Another approach is to loop through and use the pop function:

while(arr.length > 0) {
    arr.pop();
}

Answer 2

There's no need for a for loop when using the splice method, you can simply use: arr.splice(0,arr.length)

If you just want to delete all elements, you can do so by doing arr=[].

Another approach is to loop through and use the pop function:

while(arr.length > 0) {
    arr.pop();
}

Answer 3

Answer №2

If you find yourself needing to sequentially delete items from the middle of an array, it's best to iterate in reverse to avoid complications with shifting indexes.

var arr = new Array(10).fill("").map((e,i) => e = "item:" +i),
      i = 7;
console.log(JSON.stringify(arr));
while (i>2) console.log(JSON.stringify(arr.splice(i--,1))); // remove item at index i and decrease i by one
console.log(JSON.stringify(arr));

Answer 4

If you find yourself needing to sequentially delete items from the middle of an array, it's best to iterate in reverse to avoid complications with shifting indexes.

var arr = new Array(10).fill("").map((e,i) => e = "item:" +i),
      i = 7;
console.log(JSON.stringify(arr));
while (i>2) console.log(JSON.stringify(arr.splice(i--,1))); // remove item at index i and decrease i by one
console.log(JSON.stringify(arr));

What is the proper way to remove an array value using the 'splice'

Answer №1

Answer №2

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