Spread Operator
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Does ... expand an array's elements individually?
2. Can the spread operator be used to copy an array?
3. Is '..' with two dots the same as the spread operator?
4. Can the spread operator combine two arrays into one?
5. Can the spread operator be used with objects too?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1[...nums] | ACreates a new object with a copy of obj's properties | |
| 2{...obj} | BWrong - the spread operator needs exactly three dots | |
| 3Combines two arrays into a single new array | C[...arr1, ...arr2] | |
| 4Passes each array element as a separate argument | DCreates a new array with a copy of nums' elements | |
| 5let b = [..a]; | EWrong - the spread operator needs three dots, not two | |
| 6let d = [....c]; | Fconsole.log(...nums) |
C
Definitions
...
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
let copy = [___nums];
2.
let arr2 = [___arr1];
3.
let objCopy = {___obj};
4.
console.log(___nums);
5.
let newArr = [___oldArr, 4];
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
let b = [..a];
B
let a = [1, 2];
C
console.log(b);
Question 2
A
let c = [3, 4];
B
let d = [....c];
C
console.log(d);
Question 3
A
let e = {x: 1};
B
console.log(f);
C
let f = {..e};
Question 4
A
let g = [5, 6];
B
console.log(h);
C
let extra = 1;
D
let h = [...g];
Question 5
A
let i = {y: 2};
B
console.log(j);
C
let filler1 = 1;
D
let filler2 = 2;
E
let j = {...i};
Answer Key
Spread Operator
Section A: Quick Questions
Q1
A — Yes
Q2
B — Yes
Q3
A — No
Q4
B — Yes
Q5
A — Yes
Section B: Match the Pairs
Q1
[...nums] → Creates a new array with a copy of nums' elements
Q2
{...obj} → Creates a new object with a copy of obj's properties
Q3
Combines two arrays into a single new array → [...arr1, ...arr2]
Q4
Passes each array element as a separate argument → console.log(...nums)
Q5
let b = [..a]; → Wrong - the spread operator needs three dots, not two
Q6
let d = [....c]; → Wrong - the spread operator needs exactly three dots
Section C: Definitions
Q1
... — Expands an array or object's elements individually, often used to copy or combine them.Section D: Fill in the Blanks
Q1
let copy = [...nums];Q2
let arr2 = [...arr1];Q3
let objCopy = {...obj};Q4
console.log(...nums);Q5
let newArr = [...oldArr, 4];Section E: Spot the Error
Q1
A — The spread operator needs three dots, not two.
Q2
B — The spread operator needs exactly three dots, not four.
Q3
C — The spread operator needs three dots, not two.
Q4
D — This line is actually correct - ...g copies the array.
Q5
E — This line is actually correct - ...i copies the object.