Which of the following best describes the behavior of JavaScript's const keyword?
A). It prevents variables from being redeclared
B). It ensures variables cannot be reassigned
C). It provides global scope for variables
D). It allows variables to change their data type
What is the primary distinction between const and let in JavaScript?
A). const variables are immutable
B). let variables are block-scoped
C). const variables have function scope
D). let variables can be reassigned
What will be the output of the code above?
A). 10
B). 20
C). Error
D). Undefined
In JavaScript, const variables are not hoiste What does this mean?
A). They are hoisted to the top of the block
B). They cannot be used before declaration
C). They are accessible in nested scopes
D). They are block-scoped variables
How can you declare a constant named PI with a value of 3.14 in JavaScript using const?
A). const PI = 3.14;
B). PI = 3.14;
C). let PI = 3.14;
D). var PI = 3.14;
What happens if you try to reassign a value to a constant declared using const?
A). SyntaxError
B). TypeError
C). ReferenceError
D). No error, value is reassigned
What is the primary advantage of using block scope in JavaScript?
A). Reducing code size
B). Preventing variable hoisting
C). Avoiding global variables
D). Improving performance
What will be the output of the code above?
A). 30
B). 31
C). Error
D). Undefined
What will be logged to the console after executing the code above?
A). ['red', 'blue', 'green', 'yellow']
B). ['red', 'blue', 'green']
C). ['yellow']
D). Error
Which of the following statements is true about block scope in JavaScript?
A). Variables declared with let have global scope
B). Variables declared with let have function scope
C). Variables declared with let are block-scoped
D). Variables declared with let are hoisted