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 c = 70; { let c = 80; console.log(c); } console.log(c);
A). 70 80 80
B). 80 80
C). Error
D). 70 80
Can you re-declare a variable using 'const' in the same scope?
A). Yes
B). No
C). Only in functions
D). Only in loops
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: if (true) { let b = 60; } console.log(b);
A). 60
B). undefined
C). Error
D). null
How does 'let' handle variable re-declaration in the same scope?
A). Allows it
B). Silently ignores
C). Throws an error
D). Creates a new variable
Can 'const' be used to declare an array or object?
A). No, only primitives
B). Yes, but the reference can't change
C). Yes, and the content can't change
D). No
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
What will be the output of the following code: const z = 30; z = 40; console.log(z);
A). 30
B). 40
C). Error
D). undefined
What will be the output of the following code: var x = 5; var x = 10; console.log(x);
A). 5
B). 10
C). Error
D). undefined