13 More on Loops.pptx - Topic 13 More on Loops 1 Computing Total in Loop Suppose we want to find the total of numbers 1 to 4 We use the for statement to

# 13 More on Loops.pptx - Topic 13 More on Loops 1 Computing...

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Topic 13 More on Loops 1
Computing Total in Loop Suppose we want to find the total of numbers 1 to 4. We use the for statement to generate the numbers: for ( int number = 1; number <= 4; number+ + ) To find the total, we start with a total of 0 and keeping adding each number to the total until we get the total of all the numbers. 2
Computing Total in Loop total numbe r 0 0 + 1 = 1 3 1 2 3 4 5 (exit loop)
Computing Total in Loop total numbe r 0 1 1 + 2 = 3 4 1 2 3 4 5 (exit loop)
Computing Total in Loop total numbe r 0 1 3 + 3 = 6 3 5 1 2 3 4 5 (exit loop)
Computing Total in Loop total numbe r 0 1 2 3 4 5 (exit loop) 6 6 + 4 = 10 1 3 6
Computing Total in Loop Total Numbe r 7 1 2 3 4 5 (exit loop) 0 6 10 1 3
Computing Total in Loop // initialise total to 0 once before loop starts for ( int number = 1; number <= 4; number++ ) { // add each number to total in loop body } // display the total once after the loop ends 8
Computing Total in Loop int total = 0; for (int number = 1; number <= 4; number++ ) { total += number; } cout << " Total of 1 to 4 is " << total << endl; total number number <= 4 0 1 true (0+1 = ) 1 2 true (1+2 = ) 3 3 true (3+3 = ) 6 4 true (6+4 = ) 10 5 false 9
Computing Total in Loop Example – adding a set of n numbers: int n, total = 0; cout << "Enter number of values to add: "; cin >> n ; for ( int count = 1; count <= n ; count++ ) { cout << "Enter number to add: "; cin >> number; total += number; } cout << " The total is " << total << endl; 10
Computing Total in Loop 11
Computing Product in Loop Example: int n, product = 1; // cannot initialise to 0 cout << "Enter number of values to multiply: "; cin >> n; for ( int count = 0; count < n; count++ ) { cout << "Enter number to multiply: "; cin >> number; product *= number; } cout << "The product is " << product << endl; 12
Computing Product in Loop 13
14 Looping Applications In this section, we examine four common applications for loops: summation, product, smallest and largest. Although the uses for loops are virtually endless, these problems illustrate many common applications. Summation Powers Smallest and Largest Topics discussed in this section:
15 Summation and Product Loops
16 FIGURE 6-23 Smallest and Largest Loops
17 To find the largest, we need to initialize the smallest variable to a very small number, such as INT_MIN. To find the smallest, we need to initialize the result to a very large number, such as INT_MAX. Note
Finding largest value in LoopExample – finding largest in a set of nnumbers:int n, largest = INT_MIN;cout << "Enter number of values to compare: ";cin >> nfor ( int count = 1; count <= n; count++ ){cout << "Enter number to compare: ";cin >> number;if(largest < number) ; largest = number}cout << "The largest number is "<< largest << endl;18
Finding smallest value in Loop Example – finding smallest in a set of n numbers: int n, smallest = INT_MAX; cout << "Enter number of values to compare: "; cin >> n ; for ( int count = 1; count <= n ; count++ ) { cout << "Enter number to compare: "; cin >> number; if(smallest > number) smallest = number } cout << " The smallest number is " << smallest << endl; 19
Case Study 1 Problem: A company has several employees whose pay must be calculated. The total pay for all employees must also be calculated. Understand the problem: 1.