Can variables declared with 'var' be redeclared in the same scope?
A). Yes
B). No
C). Only inside a function
D). Only inside a loop
What is the correct syntax for declaring a variable in JavaScript?
A). let myVar = 5;
B). myVar let = 5;
C). 5 = let myVar;
D). let = myVar 5;
What will be the output of the following code?
var a = 1; { var a = 2; } console.log(a);
A). 1
B). 2
C). undefined
D). ReferenceError
What will be the output of the following code?
const a = 10; a = 20; console.log(a);
A). 10
B). 20
C). Error
D). undefined
What is hoisting in JavaScript?
A). Function call before declaration
B). Variable declared at the top
C). Variable and function declaration are moved to the top
D). Variable scope
Which of the following is a valid variable name in JavaScript?
A). 2name
B). _name
C). #name
D).
Which of the following will cause an error?
A). let a = 10; a = 20;
B). const a = 10; a = 20;
C). var a = 10; a = 20;
D). None of the above
Which of the following is NOT a valid variable name in JavaScript?
A). myVar
B). $myVar
C). _myVar
D). 123myVar
Which statement is true about variables in JavaScript?
A). They must be declared before use
B). They can only hold numbers
C). They are statically typed
D). They are strongly typed
What will be the output of the following code?
let a = 1; let b = 2; let c = a + b; console.log(c);
A). 12
B). 12
C). 3
D). NaN