[]=

Element Assignment

Associates the value given by value with the key given by key.

h = { "a" => 100, "b" => 200 }
h["a"] = 9
h["c"] = 4
h   #=> {"a"=>9, "b"=>200, "c"=>4}

key should not have its value changed while it is in use as a key (an unfrozen String passed as a key will be duplicated and frozen).

a = "a"
b = "b".freeze
h = { a => 100, b => 200 }
h.key(100).equal? a #=> false
h.key(200).equal? b #=> true