// Practice Set · JS Data Types (Part 2) · guest

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Question 1 of 5 from: JS NaN

What does this log?

const x = NaN;
console.log(x === x, x !== x, [NaN].includes(NaN), [NaN].indexOf(NaN));

true false true 0
false true true -1
false true false -1
true false false 0

Question 2 of 5 from: JS toLocaleString()

What does this log?

const text = (1234.5).toLocaleString("en-US");
console.log(typeof text, Number(text), Number(text.replaceAll(",", "")));

string 1234.5 1234.5
number 1234.5 1234.5
string NaN 1234.5
string NaN NaN

Question 3 of 5 from: JS Type Coercion

What does this log?

console.log("5" + 2, "5" - 2, 1 + true, [1, 2] + [3]);

7 3 2 1,23
52 52 2 6
52 3 NaN 6
52 3 2 1,23

Question 4 of 5 from: JS Type Coercion

What does this log?

console.log(0 || "default", "hi" && "there", null && "x", 0 ?? 5);

0 there null 0
default there null 0
default there x 5
default there null 5

Question 5 of 5 from: JS Type Conversion

What does this log?

console.log(Number("  42  "), parseInt("3.99"), parseFloat("3.14abc"), Number([20]), Number([10, 20]));

NaN 4 3.14 20 30
42 3.99 3.14 20 NaN
42 3 3.14 20 NaN
42 3 NaN NaN NaN

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