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
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 be the output of the following code: const d = 90; d = 100; console.log(d);
A). 90
B). 100
C). Error
D). undefined
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
Which keyword is used for declaring variables that should not change?
A). var
B). let
C). const
D). all of the above
Which keyword allows block-scoped variable declaration?
A). var
B). let
C). const
D). Both B and C
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
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: console.log(a); var a = 50;
A). 50
B). undefined
C). Error
D). null