Which of the following is true about 'const' variables in JavaScript?
A). They can be redeclared
B). They cannot be reassigned
C). They can be reassigned
D). They are always undefined
Which keyword is used to declare a variable in JavaScript?
A). var
B). let
C). const
D). All 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 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 should be used to declare a block-scoped variable?
A). var
B). let
C). const
D). Both let and const
Which of the following is correct about variable scope in JavaScript?
A). var is block-scoped
B). let is function-scoped
C). const is block-scoped
D). All variables are global
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
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?
let a = 1; let b = 2; let c = a + b; console.log(c);
A). 12
B). 12
C). 3
D). NaN
What will be the output of the following code?
let x; console.log(x);
A). null
B). undefined
C). 0
D). NaN