Selection Control Structure | C programming

Decision Making

In here you can learn different types of selection statements to select some actions. For examples if, if…else , nested if , while , switch. You can learn how to convert a given value to a specific data type and to use operators to increment, decrements and assignment.

Selection Control Structure | C programming

Selection Control Structure : if selection statement

This is the first Selection Control Structure. if statement performs an action if a condition is true. For example,

Try to do this one,

Write a program in C to read two integer numbers from the keyboard and check the numbers are equal.

Selection Control Structure : if … else Selection Statement

Another Selection Control Structure is if…else statement. This statement use to check the condition is true or false.

example for if ... else Selection Statement — example for if … else Selection Statement

Try to do this one,

Write a program in C to read two integer numbers from the keyboard and display the highest number.

Selection Control Structure : Nested if … else statement

This statement handle multiple cases by placing if … else statements. There are two ways to code it. For example,

example for Nested if ... else statement- part 01 — example for Nested if … else statement- part 01

You can code like this also,

example for Nested if ... else statement- part 02 — example for Nested if … else statement- part 02

Switch Statement in c programming

This statement is an alternative to the nested if… else statement. In here we consists of a series of case labels. So multiple statements can be executed for a given condition and we use break statement to terminate the execution of a condition. For example,

Cast operator in c programming

Cast operators force the conversation of a value to a specific type. It means you can convert one data type to another data type. For an example, you want to convert integer value to float,

In here you can see the total value is a integer type variable. also the size variable is a integer type variable. But the variable called average is a float type. “total / size” will give you the integer value. Because of those two variables are integer. So you can use Cast operator to solve this problem.

Conditional Operator in c programming

This is also related to if…else statement. For example,

This has 3 steps in one line. First is a condition. Then the 2nd step is the value if the condition is true. Last step is the value if the condition is false. Above statement is same as,

if( mark >= 60 ){

printf(“passed”);

}else{

printf(“Failed”);

}

So if you want to code a program with minimum lines, Do this operator.

Assignment Operators in c programming

For example,

k = ++n //increment n = n + 1; then k = n;
k = n++ //increment k = n ; then n = n + 1;
k = –n //decrements n = n – 1; then k = n;
k = n– //decrements k = n; then n = n – 1;

Do the following quiz (no = 10 and x = 5 )

no -= 4 ;
printf( “%d, %d”, x++, no–) ;
x–
no+++

Logical Operators in c programming

for the logical operation “AND” we use “&&” operator. This operator evaluates if the two conditions are true. For example, if( (avg > 75) && ( age > 18 ) )
for the logical operation “OR” we use “||” operator. This one evaluates if a one condition is true. For example, if( (avg > 75) || ( avg > 65 ) )
for the logical operation “NOT” we use “!”. For example, if( count != 10 )

Do the following quiz ( no = 5 , size = 9 ),