What are expressions in C?
An expression in C is a combination of operands and operators – it computes a single value stored in a variable. The operator denotes the action or operation to be performed. The operands are the items to which we apply the operation.
An expression can be defined depending on the position and number of its operator and operands:
- Infix Expression (operator is used between the operands)
a = x + y
- Postfix Expression (operator is used after the operands)
xy+
- Prefix Expression (operator is used before the operands)
+xy
- Unary Expression (one operator and one operand)
x++
- Binary Expression (one operator and two operands)
x+y
Types of Expression
There are six types of expressions. These are shown below:
Arithmetic expression
It consists of arithmetic operators ( + , - , * , and / ) and computes values of int, float, or double type.
#include <stdio.h>int main(){//Arithmetic Expressionint a = (6 * 2) + 7 - 9;printf("The arithmetic expression returns: %d\n", a);return 0;}
Relational expression
It usually consists of comparison operators (> , < , >= , <= , === , and !== ) and computes the answer in the bool type, i.e., true (1) or false (0).
#include <stdio.h>int main(){//Relational Expressionint b = 10;printf("The relational expression returns: %d\n", b % 2 == 0);return 0;}
Logical expression
It consists of logical operators (&&, ||, and !) and combines relational expressions to compute answers in the bool type.
#include <stdio.h>int main(){//Logical Expressionint c = (7 > 9) && ( 5 <= 9);printf("The logical expression returns: %d\n", c);return 0;}
Conditional expression
It consists of conditional statements that return true if the condition is met and false otherwise.
#include <stdio.h>int main(){//Conditional Expressionint d = (34 > 7) ? 1 : 0;printf("The conditional expression returns: %d\n", d);return 0;}
Pointer expression
It may consist of an ampersand (&) operator and returns address values.
#include <stdio.h>int main(){//Pointer Expressionint e = 20;int *addr = &e;printf("The pointer expression returns: %p\n", addr);return 0;}
Bitwise expression
It consists of bitwise operators ( >>, <<, ~, &, |, and ^ ) and performs operations at the bit level.
#include <stdio.h>int main(){//Bitwise Expressionint f = 10;int shift = 10 >> 1;printf("The bitwise expression returns: %d\n", shift);return 0;}
Expressions play a pivotal role in manipulating data and enabling logical and mathematical operations within C programs, forming the core of computational tasks in the language.
