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

Chapter 8 ■ Arrays
The complete program is shown as Program P8.2. It reads data from the file passage.txt and
sends output to the file output.txt.
Program P8.2
#include <stdio.h>
#include <ctype.h>
int main() {
char ch;
int n, letterCount[27], position(char);
FILE * in = fopen("passage.txt", "r");
FILE * out = fopen("output.txt", "w");
for (n = 1; n <= 26; n++) letterCount[n] = 0; //set counts to 0
while ((ch = getc(in)) != EOF) {
n = position(ch);
if (n > 0) ++letterCount[n];
}
//print the results
fprintf(out, "Letter Frequency\n\n");
for (n = 1; n <= 26; n++)
fprintf(out, "%4c %8d\n", 'a' + n - 1, letterCount[n]);
fclose(in);
fclose(out);
} //end main
int position(char ch) {
if (isupper(ch)) return ch - 'A' + 1;
if (islower(ch)) return ch - 'a' + 1;
return 0;
} //end position
Suppose passage.txt contains the following:
The quick brown fox jumps over the lazy dog.
If the quick brown fox jumped over the lazy dog then
Why did the quick brown fox jump over the lazy dog?
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