3 ms·
Not true. slice() clones-and-drops the array, but not the objects inside.
by brundolf 5y ago
Not true. slice() clones-and-drops the array, but not the objects inside.
- darepublic 5y agobut map also creates a new array, and within map you are not mutating the items of the old array but creating brand new ones no? [...].map(p => ({...p, canDrink})) ^ the original items of the array are not mutated in this map callback. you could mutate them if you really wanted, i.e. [...].map(p => {p.canDrink = p.age > 20; return p}) but that is a straight up hack.