C Programming Absolute Beginner’s Guide, Third Edition

12. Juggling Several Choices with Logical Operators

In This Chapter

• Getting logical

• Avoiding the negative

• The order of logical operators

Sometimes the relational operators described in Chapter 11, “The Fork in the Road—Testing Data to Pick a Path,” simply can’t express all the testing conditions. For example, if you wanted to test whether a numeric or character variable is within a certain range, you would have to use two if statements, like this:

Click here to view code image

if (age >= 21) /* See if 21 <= age <= 65 */{ if (age <= 65)    {    printf("The age falls between 21 and 65.\n");    }}

Although there’s nothing wrong with using nested if statements, they’re not extremely straightforward, and their logic is slightly more complex ...