Variable | MCQs

Explanation

A variable is a named memory location whose value can change during the execution of a program.

In contrast, a constant has a fixed value that does not change while the program runs.

Explanation

cin >> age; is the correct syntax in C++ to take input from the user and store it in the variable age.

The >> operator is used with cin to extract the input value into the variable.

Explanation

In z = z + y;, since z is an int and y is long, y is converted to int (if possible) to match the type of z due to usual type conversion rules.

The result is calculated as an int, and this may cause data loss if y exceeds int range.

Explanation

A variable declared with the const keyword in C becomes read-only and its value cannot be modified after initialization.

Attempting to change a const variable will result in a compile-time error.

Explanation

"define" is a reserved keyword in C, used in preprocessor directives (e.g., #define) and cannot be used as a variable name.

Variable names like "address", "name", and "age" are valid as they follow C naming rules and aren't reserved.

Explanation

For using a variable in C++, we have to first define it to tell the compiler about its existence so that compiler can allocate the required memory to it.

AGM 24-12-2022

Explanation

Lifetime of a variable is the time for which the variable is taking up a valid space in the system's memory.

Explanation

Variable scope refers to the extent of code in which a variable can be referenced.

Variables defined inside a function are called local variables.

The scope of local variables and dummy arguments is limited to the function in which they are defined.

Explanation

The format specifier %c is used in scanf to read a single character.

So, km must be a character variable, e.g., char km;.

Explanation

The function used to get values into variables from the keyboard is scanf().

It reads input from the standard input (usually the keyboard) and stores it in the specified variables.