swift - Immutable Dictionary value change -

swift - Immutable Dictionary value change -

can alter pair value in allow type dictionary in swift langauage.

like :

let arr2 : anyobject[] = [1, "23", "hello"] arr2[1] = 23 arr2 // output: [1,23,"hello"] allow arr1 :dictionary<int,anyobject> = [1: "one" , 2 : 2] arr1[2] = 4 // not posible error arr1

in case of immutable array can alter value above not in case of immutable dictionary. why?

this taken swift programming language book:

for dictionaries, immutability means cannot replace value existing key in dictionary. immutable dictionary’s contents cannot changed 1 time set.

immutability has different meaning arrays, however. still not allowed perform action has potential alter size of immutable array, allowed set new value existing index in array.

swift