immutable operations on array in javascript

slice-magic.js

const a = [1,2,3];

// Remove Elements from index
const index = 1;
const b = [ ...a.slice(0, index), ...a.slice(index + 1, a.length),  ];

console.log('a',a);
console.log('b',b);


// Add Element to index
const index2 = 1;
const val = 5;
const b2 = [ ...a.slice(0, index2), val ,...a.slice(index2, a.length),  ];

console.log('a',a);
console.log('b',b2);



console.log('', b2.slice(0, 0));


// console.log([1,2,3].slice(1,3));