Conditional Statements in C programming make decisions based on the given conditions in the command. They are executed in order or in a sequence when there is no condition around the statements. Thus, they are ‘decision making’ statements in C.
We can write conditional statements in C in these two ways:
1. If statement 2. If-else statement They are branching statements as they make a decision depending on the condition.
If Statement
If statement is one of the powerful conditional statements. They are responsible for modifying the flow of execution of a program. And, the condition is evaluated followed by which any statement inside the body of If is excecuted. Syntax: The condition is given a true or false value. True – non-zero value False – zero value
if (condition)
instruction;
Example: If construct to check if 2 numbers are equal
Output:
num1 is smaller than num2
Relational Operators
C has six relational operators. They can be used to formulate a Boolean expression for decision making and testing conditions. This returns true or false :
- < less than
- <= less than or equal to
- > greater than
- >= greater than or equal to
- == equal to
- != not equal to
The equal test (==) is different from the assignment operator (=).
Example:
int x = 41;
x =x+ 1;
if (x == 42) {
printf("You succeed!");}
Output :
You succeed
If-Else statement: extended if
Syntax:
if (test-expression)
{
True block of statements
}
Else
{
False block of statements
}
Statements;
Example:
Output:
The value is greater than 10
Nested If-Else-if statements
When multipath decisions are needed to be taken, we use nested if else if.
Syntax:
if (test - expression 1) {
statement1;
} else if (test - expression 2) {
Statement2;
} else if (test - expression 3) {
Statement3;
} else if (test - expression n) {
Statement n;
} else {
default;
}
Statement x;
Example: Program to print the grade depending on scored marks.
Output:
First class
