What does this log?

const d = JSON.parse('{"a":[1,2],"b":null,"c":"x"}');
console.log(typeof d.a, Array.isArray(d.a), d.b, typeof d.c);

1. object true null string
2. object true undefined string
3. array true null string
4. object false null string

What does this log?

console.log(JSON.stringify({ a: 1, b: undefined, c: [undefined, NaN] }));

1. {"a":1,"b":undefined}
2. {"a":1,"c":[null,null]}
3. {"a":1,"c":[]}
4. {"a":1,"b":null,"c":[null,null]}

fetch("missing.json") asks a working server for a file that does not exist, and the server answers 404. What happens?

1. The promise still resolves with a response: check response.ok yourself
2. fetch retries until the file appears
3. The promise rejects, so a catch runs
4. The page crashes

A script on a page uses document.getElementById("list") but the <ul id="list"> comes AFTER the script. What goes wrong?

1. The script runs after the page closes
2. The element does not exist yet when the script runs, so the lookup finds nothing
3. The list shows twice
4. Nothing: the order never matters

In XML, every value is text unless the program reading it converts it.

1. True
2. False