Page 51 - DCAP404 _Object Oriented Programming

Object-oriented Programming

Notes where expression-1 is used to initialize some parameter (called an index) that controls the
looping action, expression-2 represents a condition that must be true for the loop to continue
execution, and expression-3 is used to alter the value of the parameter initially assigned by
expression-1. Typically, expression-1 is an assignment expression, expression-2 is a logical
expression and expression-3 is a unary expression or an assignment expression.
When the for statement is executed, expression-2 is evaluated and tested at the beginning of each
pass through the loop, and expression-3 is evaluated at the end of each pass. Thus, the for
statement is equivalent to
Expression-1;

while (expression-2)
{
statement
expression-3;
}
The looping action will continue as long as the value of expression-2 is not zero, that is as long
as the logical condition represented by expression-2 is true.
The program will display the consecutive duals using for loop.
# include < stdio. h>
main ( ) /* display the numbers 0 through 9*/
{
int digit

for ( digit = 0 , digit < = 9; + + digit)
printf ( “ % d\n” , digit);
}
The first line of the for statement contains three expression, enclosed in parentheses. The first
expression assigns an initial value 0 to the integer variable digit; the second expression continues
the looping action as long as the current value of digit does not exceed 9 at the beginning of each
pass, and the third expression increases the value of digit by 1 at the end of each pass through the
loop.

Task The for statement is ideal when we know exactly how many times we need to
iterate, because it lets us easily declare, initialize, and change the value of loop variables
after each iteration. Analyze and explain with an example.

Self Assessment

Fill in the blanks:
9. The ……………………….. is used to carry out a logical test and then take on of two possible
actions, depending on the outcome of the test.

10. The …………………… statement is used to carry out operations, in which a group of
statements is executed repeatedly, till a condition is satisfied.

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