var list = ["A"];
list[0] += "B";
print(list); # expect: [AB]


list = [5];
var index = 0;
print(list); # expect: [5]
list[0] = 6;
print(list); # expect: [6]
list[index] *= 2;
print(list); # expect: [12]
list[0] *= "Test"; # expect runtime error: Operands must be numbers. Got: [12, Test]
print(list);