#1
Which keyword is used to declare a variable in JavaScript?
let
ExplanationDeclares a variable with block scope.
#2
What is the purpose of variable initialization?
To assign an initial value to the variable
ExplanationAssigns an initial value to a variable.
#3
Which of the following is true about variable names in Java?
Variable names are case-sensitive
ExplanationVariable names in Java are case-sensitive.
#4
What is the default value of an uninitialized integer variable in Java?
0
ExplanationDefaults to 0 in Java when uninitialized.
#5
In JavaScript, what does the 'const' keyword do when declaring a variable?
Specifies that the variable cannot be reassigned
ExplanationSpecifies immutability, preventing reassignment in JavaScript.
#6
What is the result of dividing by zero in most programming languages?
Throws an error
ExplanationResults in an error when attempting to divide by zero.
#7
In Python, what does the 'None' keyword represent when initializing a variable?
A null value
ExplanationRepresents a null value when initializing a variable in Python.
#8
What is the scope of a variable declared using the 'let' keyword in JavaScript?
Block scope
ExplanationHas block scope in JavaScript.
#9
What does the 'extern' keyword signify in C programming language?
Declares a variable to be of external linkage
ExplanationDeclares a variable with external linkage in C.
#10
In Python, what is the result of trying to access a variable before it's been initialized?
NameError
ExplanationResults in a NameError in Python.
#11
In C#, how can you declare and initialize a variable in a single line?
var x = 10;
ExplanationUses 'var' to declare and initialize a variable in a single line in C#.
#12
What is the purpose of the 'static' keyword when declaring a variable in C++?
Specifies that the variable belongs to the class itself rather than instances of the class
ExplanationSpecifies class-level ownership rather than instance-level in C++.
#13
In C++, what does the 'auto' keyword do when declaring a variable?
Automatically deduces the data type of the variable
ExplanationAutomatically deduces the data type of the variable in C++.
#14
What is the purpose of the 'volatile' keyword in C++?
Indicates that a variable's value may be changed unexpectedly
ExplanationIndicates potential unexpected changes in a variable's value in C++.
#15
In Java, which of the following is an invalid variable name?
123variable
ExplanationInvalid variable name in Java due to starting with a digit.
#16
In C++, what does the 'mutable' keyword allow for a member variable?
Allows the variable to be modified even in a const member function
ExplanationAllows modification of a variable in a const member function in C++.
#17
In Java, which access modifier is used to restrict access to variables within the same package?
default
ExplanationRestricts access to variables within the same package using the 'default' access modifier in Java.