Which keyword should be used to declare a block-scoped variable?
A). var
B). let
C). const
D). Both let and const
What is the difference between let and var?
A). let is function-scoped, var is block-scoped
B). let is block-scoped, var is function-scoped
C). Both are block-scoped
D). Both are function-scoped
Which of the following is NOT a valid variable name in JavaScript?
A). myVar
B). $myVar
C). _myVar
D). 123myVar
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 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?
var a = 1; { var a = 2; } console.log(a);
A). 1
B). 2
C). undefined
D). ReferenceError
Which keyword is used to declare a variable in JavaScript?
A). var
B). let
C). const
D). All of the above
What will be the output of the following code?
console.log(a); var a = 10;
A). 10
B). undefined
C). Error
D). null
Can you reassign a value to a variable declared with let?
A). Yes
B). No
C). Only in strict mode
D). Only inside a block
Which of the following is a valid variable name in JavaScript?
A). 2name
B). _name
C). #name
D).