Variables: let, const, var
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. Can a variable declared with let be reassigned later?
2. Can a variable declared with const be reassigned later?
3. Is 'var' the modern, preferred way to declare variables?
4. Does 'let count = 5;' declare a variable named count?
5. Can you redeclare the same variable name with let twice?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1let age = 12; | Avar total = 100; | |
| 2const name = "Sam"; | Bconst | |
| 3The older, less preferred way to declare variables | CWrong - the keyword 'let' must be lowercase | |
| 4Signals to other developers that a value is fixed | DDeclares a variable that can never be reassigned | |
| 5const pi = 3.14; pi = 3.15; | EDeclares a variable that can change later | |
| 6LET score = 0; | FWrong - const variables can't be reassigned |
C
Definitions
let
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
___ age = 12
2.
_____ name = "Sam"
3.
let score = 0;
score = score _ 1
4.
___ total = 100
5.
_____ pi = 3.14
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
let age = 12;
B
cnst name = "Sam";
C
age = 13;
Question 2
A
const pi = 3.14;
B
let score = 0;
C
score = score + 1;
D
let count = 5;
E
pi = 3.15;
Question 3
A
LET total = 10;
B
let count = 5;
C
count = 6;
Question 4
A
var oldWay = 1;
B
let modernWay = 2;
C
const modernWay = 3;
Question 5
A
const name = "Sam";
B
let age = 12;
C
age == 13;
Answer Key
Variables: let, const, var
Section A: Quick Questions
Q1
A — Yes
Q2
A — No
Q3
B — No
Q4
B — Yes
Q5
A — No
Section B: Match the Pairs
Q1
let age = 12; → Declares a variable that can change later
Q2
const name = "Sam"; → Declares a variable that can never be reassigned
Q3
The older, less preferred way to declare variables → var total = 100;
Q4
Signals to other developers that a value is fixed → const
Q5
const pi = 3.14; pi = 3.15; → Wrong - const variables can't be reassigned
Q6
LET score = 0; → Wrong - the keyword 'let' must be lowercase
Section C: Definitions
Q1
let — Declares a variable whose value can be changed later.Section D: Fill in the Blanks
Q1
let age = 12Q2
const name = "Sam"Q3
let score = 0;
score = score + 1Q4
var total = 100Q5
const pi = 3.14Section E: Spot the Error
Q1
B — 'const' is misspelled as 'cnst'.
Q2
E — const values cannot be reassigned after they're set.
Q3
A — 'let' must be lowercase - a capital L causes an error.
Q4
C — You can't redeclare 'modernWay' - it's already declared with let.
Q5
C — Assignment uses a single =, not the comparison operator ==.