Learn to Program with C_ Learn to Program using the Popular C Programming Language ( PDFDrive )

Chapter 5 ■ Programs with Repetition Logic
We will then add lastName with
strcat(name, lastName);
Using our example, at the end of all this, name will contain Robin Hood.
In our program, we will use the specification %-15s to print name. This will print name left
justified in a field width of 15. In other words, all names will be printed using 15 print columns.
This is necessary for the output to line up neatly. To cater for longer names, you can increase the
field width.
To use the string functions, we must write the directive
#include <string.h>
at the head of our program if we want to use the string functions supplied by C.
Our program will need to check if the value in firstName is the string "END". Ideally, we
would like to say something like
while (firstName != "END") { //cannot write this in C
but we cannot do so since C does not allow us to compare strings using the relational operators.
What we can do is use the predefined string function strcmp (string compare).
If s1 and s2 are strings, the expression strcmp(s1, s2) returns the following values:
• 0 if s1 is identical to s2
• < 0 if s1 is less than s2 (in alphabetical order)
• > 0 if s1 is greater than s2 (in alphabetical order)
For example,
strcmp("hello", "hi") is < 0
strcmp("hi","hello") is > 0
strcmp("allo","allo") is 0
Using strcmp, we can write the while condition as
while (strcmp(firstName, "END") != 0)
If strcmp(firstName, "END") is not 0, it means that firstName does not contain the
word END so we have not reached the end of the data; the while loop is entered to process that
employee.
When faced with a program that requires so many things to be done, it is best to start by
working on part of the problem, getting it right, and then tackling the other parts. For this
problem, we can start by getting the program to read and process the data without counting,
finding the total or finding the highest-paid employee.
Program P5.8 is based on program P4.7 (Section 4.6.2).
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