e.g. a number
const constNum = 0;
constNum = 1;
assert.equal(constNum, 0);or a string
const constString = 'I am a const';
constString = 'Cant change you?';
assert.equal(constString, 'I am a const');
complex types are NOT fully read-only
array's items can be changed
const arr = [];
arr[0] = 0;
assert.equal(arr[0], 42);object's can be modified
const obj = {x: 1};
obj.x = 2;
assert.equal(obj.x, 3);