Absolute Beginner's Guide to Programming, Third Edition

Swapping Values

The cornerstone of any sorting algorithm is data swapping. As you sort data, you have to rearrange it, swapping higher values for lower values. As Figure 12.1 shows, swapping values simply means replacing one variable's contents with another's and vice versa.

Figure 12.1. Learn to swap two variable values with code.

Suppose you assign two variables named var1 and var2 with the following statements:

var1 = 65
var2 = 97

The concept of swapping them is simple. How would you do it? If you said the following, you would not be quite correct:

var1 = var2   ' Not quite accurate
var2 = var1

Can you see why these two assignment statements ...