Which keyword allows block-scoped variable declaration?
A). var
B). let
C). const
D). Both B and C
What will be the output of the following code: if (true) { let b = 60; } console.log(b);
A). 60
B). undefined
C). Error
D). null
What will happen if you declare a variable without 'var', 'let', or 'const'?
A). Creates a global variable
B). Creates a block-scoped variable
C). Creates a function-scoped variable
D). Throws an error
How does 'let' differ from 'var' in terms of scope?
A). No difference
B). Function-scoped
C). Block-scoped
D). Global-scoped
What will be the output of the following code: let c = 70; { let c = 80; console.log(c); } console.log(c);
A). 70 80 80
B). 80 80
C). Error
D). 70 80
What will be the output of the following code: const d = 90; d = 100; console.log(d);
A). 90
B). 100
C). Error
D). undefined
Which keyword should be used by default to declare variables in modern JavaScript?
A). var
B). let
C). const
D). Either B or C
What will be the output of the following code: let y = 10; let y = 20; console.log(y);
A). 10
B). 20
C). Error
D). undefined
What will be the output of the following code: var e = 110; if (true) { var e = 120; } console.log(e);
A). 110
B). 120
C). Error
D). undefined
How do 'var' declarations handle hoisting?
A). They are not hoisted
B). Only the assignment is hoisted
C). Only the declaration is hoisted
D). Both declaration and assignment are hoisted