Arrays – forEach()
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Does forEach() call a function once for each array element?
2. Is 'forEach' spelled with a capital E in the middle?
3. Does forEach() need a function passed to it?
4. Is 'ForEach' with a capital F valid JavaScript syntax?
5. Does forEach() return a new array?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1fruits.forEach(function(fruit) { ... }) | APrints every number in nums, one at a time | |
| 2nums.forEach(function(n) { console.log(n); }) | BCalls the function once for each element in fruits | |
| 3Runs a function once for every element in an array | CWrong - missing the 'function' keyword before the parameter | |
| 4Holds the current element's value during each call | Darray.forEach(function(item) { ... }) | |
| 5fruits.ForEach(function(fruit) { ... }) | EWrong - 'forEach' must start with a lowercase f | |
| 6fruits.forEach(fruit) { ... } | Ffruit |
C
Definitions
forEach()
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
fruits._______(function(fruit) {
2.
fruits.forEach(________(fruit) {
3.
colors._______(function(color) {
4.
colors.forEach(________(color) {
5.
nums._______(function(n) {
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
a.ForEach(function(x) {
B
let a = [1, 2];
C
console.log(x);
Question 2
A
let b = [1, 2];
B
b.foreach(function(x) {
C
console.log(x);
Question 3
A
let c = [1, 2];
B
c.forEach(function(x) {
C
console.log(x)
D
});
Question 4
A
let d = [1, 2, 3];
B
d.forEach(function(x) {
C
console.log(x);
D
]
Question 5
A
let e = [1, 2];
B
console.log(e);
C
let f2 = 3;
D
e.forEach((x) {
E
console.log(x);
Answer Key
Arrays – forEach()
Section A: Quick Questions
Q1
B — Yes
Q2
B — Yes
Q3
A — Yes
Q4
A — No
Q5
A — No
Section B: Match the Pairs
Q1
fruits.forEach(function(fruit) { ... }) → Calls the function once for each element in fruits
Q2
nums.forEach(function(n) { console.log(n); }) → Prints every number in nums, one at a time
Q3
Runs a function once for every element in an array → array.forEach(function(item) { ... })
Q4
Holds the current element's value during each call → fruit
Q5
fruits.ForEach(function(fruit) { ... }) → Wrong - 'forEach' must start with a lowercase f
Q6
fruits.forEach(fruit) { ... } → Wrong - missing the 'function' keyword before the parameter
Section C: Definitions
Q1
forEach() — Calls a given function once for every element in an array.Section D: Fill in the Blanks
Q1
fruits.forEach(function(fruit) {Q2
fruits.forEach(function(fruit) {Q3
colors.forEach(function(color) {Q4
colors.forEach(function(color) {Q5
nums.forEach(function(n) {Section E: Spot the Error
Q1
A — 'forEach' must start lowercase - capital F causes an error.
Q2
B — 'forEach' needs a capital E - 'foreach' is wrong casing.
Q3
C — This line is missing a semicolon, but that's not required in JS.
Q4
D — The block must close with }, not ].
Q5
D — Missing the 'function' keyword before the parameter.