let x; console.log(x);
Which keyword should be used to declare a block-scoped variable?
A). var
B). let
C). const
D). Both let and const
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
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 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 keyword is used to declare a variable in JavaScript?
A). var
B). let
C). const
D). All of the above
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
Which of the following is true about variable naming conventions in JavaScript?
A). Variable names can start with a number
B). Variable names are case-insensitive
C). Variable names can include spaces
D). Variable names are case-sensitive
What will be the output of the following code?
var x = 5; var y = 6; var z = x + y;
A). 11
B). 11
C). 5
D). 6
What will be the output of the following code?
console.log(a); var a = 10;
A). 10
B). undefined
C). Error
D). null
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;