So far, we have seen that all the statements in a C program gets executed sequentially in the order in which they are written and appear.
Decision power enable the deciding order of execution of statements based on certain conditions or repeat a group of statements until certain specified conditions are met.
We will learn to change the order of execution of statements in this chapter and repetition in next program.
Add decision power to computerC Branching
This enable us to specify conditions inside the program ,so computer will perform certain function only if the condition is meet.
We generally have 4 types of Branching statements :
- if statement
- switch statement
- conditional operator statement (? : operator)
- goto statement
Single Conditional Branching
Here is a simple C program demonstrating an if statement:
This program accepts a number from the user. It then tests the number using an if statement to see if it is less than 0. If it is, the program prints a message. Otherwise, the program is silent. The (b < 0) portion of the program is the Boolean expression. C evaluates this expression to decide whether or not to print the message. If the
Boolean expression evaluates to True, then C executes the single line immediately following the if statement (or a block of lines within braces immediately following the if statement). If the Boolean expression is False, then C skips the line or block of lines immediately following the if statement.