Understand While Loop in C Language

While loop

It is often the case in programming that you want to repeat something a fixed number of time. Perhaps you want to calculate gross series of ten different persons, or you want to convert temperatures from centigrade to Fahrenheit for 15 different cities. The while loop is ideally suited for this.

 General form of WHILE LOOP statement:

Note the following points about WHILE…..

Ø  The statement within the while loop will keep getting executed till the condition being tested remain true. When the condition become false, the control passes to the first statement that flows the body of the WHILE LOOP.

Ø  In place of the condition, there can be any other valid expression. So long as the expression evaluates to a non-zero value, the statements within the loop would get executed.

Ø  The condition being tested may use relational or logical operators as show in above example: while(i<=10)

while(i>=10&&j<=15)

while(i>10&&(b<15||c<20))

Ø  The statement within the loop may consist a single line or a block of statement. In the first case, the braces are optional.

Ø  Almost always, the while must test a condition that will eventually become false, otherwise the loop would keep getting executed forever, indefinitely.

Ø  Instead of incrementing a loop counter, we can decrement it and still manage to get the body of the loop executed repeatedly.

Ø  It is not necessary that a loop counter must only be an int. it can even be a float.

Ø  Even floating point counters can be decremented. Once again the increment and decrement could be any value, not necessarily 1.