C Language Basics Quiz

Declarations of Variables

• In C, a variable must be declared before it can be used
• Declaration of a variable specifies its type and identifier (name)
• Example: int x; declares an integer variable named x
• Variables can be declared with an initial value using the assignment operator (=)
• Example: int x = 10; declares an integer variable named x and initializes it with the value 10

Data Types

• C has multiple data types, including:
  • int: whole numbers (e.g. 1, 2, 3, etc.)
  • float: decimal numbers (e.g. 3.14, -0.5, etc.)
  • char: single characters (e.g. 'a', 'B', etc.)
  • double: double precision decimal numbers (e.g. 3.14159, -0.00005, etc.)

Assignment Operator

• The assignment operator (=) is used to assign a value to a variable
• Example: x = 10; assigns the value 10 to the variable x
• The assignment operator can also be used with expressions
• Example: x = 5 + 5; assigns the result of the expression 5 + 5 to the variable x

Incremental and Decrement Operators

• Incremental operator (++) increases the value of a variable by 1
• Example: x++; increases the value of x by 1
• Decremental operator (--) decreases the value of a variable by 1
• Example: x--; decreases the value of x by 1
• These operators can be used in both prefix and postfix forms
• Example: ++x and x++ both increase the value of x by 1, but have different effects on the value of the expression

Logical Operators

• Logical operators are used to combine conditional statements
• There are three logical operators:
  • && (logical AND): true if both operands are true
  • || (logical OR): true if at least one operand is true
  • ! (logical NOT): true if the operand is false
• Example: if (x > 5 && x < 10) { ... } executes the code inside the if statement if x is between 5 and 10

Relational Operators

• Relational operators are used to compare values
• There are six relational operators:
  • == (equal to)
  • != (not equal to)
  • > (greater than)
  • < (less than)
  • >= (greater than or equal to)
  • <= (less than or equal to)
• Example: if (x > 5) { ... } executes the code inside the if statement if x is greater than 5