__len__()?",
options: [
"len()",
"size()",
"count()"
],
correct: 0
},
{
question: "What must __len__() return?",
options: [
"A string",
"A number",
"A list"
],
correct: 1
},
{
question: "Without __len__(), what happens if you call len(obj) on a custom object?",
options: [
"It returns 0",
"It raises a TypeError",
"It returns None"
],
correct: 1
}
]