for...of Loops
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Does for...of loop through each value in an array?
2. Does for...of require the keyword 'of'?
3. Is 'in' the same as 'of' in this kind of loop?
4. Does for...of need a variable name to hold each value?
5. Must 'for' be written in lowercase?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1for (let fruit of fruits) { ... } | AGives direct access to each value in nums, not the index | |
| 2for (let n of nums) { ... } | Blet fruit | |
| 3Loops directly over each value in an array | CWrong - use 'of', not 'in', to loop through values | |
| 4Holds the current value during each pass of the loop | Dfor...of | |
| 5for (let n in nums) { ... } | EWrong - 'for' must be lowercase | |
| 6For (let n of nums) { ... } | FLoops through each value in the fruits array |
C
Definitions
for...of
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
___ (let fruit of fruits) {
2.
for (let fruit __ fruits) {
3.
___ (let color of colors) {
4.
for (___ item of items) {
5.
for (let num of nums) _
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
Fr (let x of arr) {
B
console.log(x);
C
}
Question 2
A
let arr = [1,2,3];
B
for (let x in arr) {
C
console.log(x);
D
}
Question 3
A
let list = [1,2,3];
B
for (let v of list) {
C
conssole.log(v);
D
}
Question 4
A
let nums = [1,2,3];
B
for (let n of nums) {
C
console.log(n);
D
]
Question 5
A
let a = [1,2];
B
for (let x of a) {
C
console.log(x);
D
console.log("done");
E
]
Answer Key
for...of Loops
Section A: Quick Questions
Q1
A — Yes
Q2
A — Yes
Q3
A — No
Q4
B — Yes
Q5
B — Yes
Section B: Match the Pairs
Q1
for (let fruit of fruits) { ... } → Loops through each value in the fruits array
Q2
for (let n of nums) { ... } → Gives direct access to each value in nums, not the index
Q3
Loops directly over each value in an array → for...of
Q4
Holds the current value during each pass of the loop → let fruit
Q5
for (let n in nums) { ... } → Wrong - use 'of', not 'in', to loop through values
Q6
For (let n of nums) { ... } → Wrong - 'for' must be lowercase
Section C: Definitions
Q1
for...of — Loops directly over each value in an array, without needing an index.Section D: Fill in the Blanks
Q1
for (let fruit of fruits) {Q2
for (let fruit of fruits) {Q3
for (let color of colors) {Q4
for (let item of items) {Q5
for (let num of nums) {Section E: Spot the Error
Q1
A — 'for' is misspelled as 'Fr'.
Q2
B — Use 'of', not 'in', to loop through array values.
Q3
C — 'console' is misspelled as 'conssole'.
Q4
D — The block must close with }, not ].
Q5
E — The block must close with }, not ].