Immutability means not changing the data, not changing the state.
In functional programming, the idea of immutability is not changing the state, instead taking copies of the state and returning a new state every time.
Ex:
const obj = { name: 'Vijay' };
function clone(obj) {
return { ...obj }; // this is pure
}
// obj.name = 'Nana'; // mutating the data
// insted mutating create function to update name
function updateName(obj) {
const newObj = clone(obj);
newObj.name = 'Nana';
return newObj;
}
const updatedbj = updateName(obj);
console.log(obj, updatedbj); // { name: 'Vijay' } { name: 'Nana' } // immutability
