JavaScript

Install nodejs

sudo n stable

const one = [0, 1, 2];
const two = one;
two.push(3);
 
console.log(one);
console.log(two);

output:

[ 0, 1, 2, 3 ]
[ 0, 1, 2, 3 ]

Note: slice works on arrays of primitives not objects

const one = [0, 1, 2];
const two = one.slice();
two.push(3);
 
console.log(one);
console.log(two);

output:

[ 0, 1, 2 ]
[ 0, 1, 2, 3 ]

But objects will still refer to the original arrays even with slice

const one = [ { name: 'kalen', age: 23 }, { name: 'kailyn', age: '22', } ]; const two = one.slice(); two.name = 'Patrick'; console.log(one); console.log(two);

output:

[ { name: 'Patrick', age: 23 }, { name: 'kailyn', age: '22' } ]
[ { name: 'Patrick', age: 23 }, { name: 'kailyn', age: '22' } ]