CODEWITHSUNDEEP
c
jsampedro
jsampedro

Reputation: 85

C Programming Language Exercise 1.5.4 (editing error found in code?)

I'm continue working with the Classic K&R Book "The C Programming Language", Second Edition.

SCENE.

I was having problems with the output of exercise in page 22 about word counting. Not getting the desired output.

QUESTION.

Finally I think that found a mistake in the code syntax ?

CODE FRON ORIGINAL PDF.

Exercise say (Copy and paste from PDF):

1.5.4 Word Counting The fourth in our series of useful programs counts lines, words, and characters, with the loose definition that a word is any sequence of characters that does not contain a blank, tab or newline. This is a bare-bones version of the UNIX program wc.

#include <stdio.h>

#define IN 1 /* inside a word */
#define OUT 0 /* outside a word */

/* count lines, words, and characters in input */
main()
{
    int c, nl, nw, nc, state;

    state = OUT;
    nl = nw = nc = 0;
    while ((c = getchar()) != EOF) {
        ++nc;
        if (c == '\n')
            ++nl;
        if (c == ' ' || c == '\n' || c = '\t')
           state = OUT;
        else if (state == OUT) {
           state = IN;
           ++nw;
        }
    }
    printf("%d %d %d\n", nl, nw, nc);
}

CHANGE NEDED TO WORK

Where Say:

if (c == ' ' || c == '\n' || c = '\t')

No need to say?

if (c == ' ' || c == '\n' || c == '\t')

Please.

If my assessment is correct. The same error appears later on page 23 which explains the line.

CONFIRMATION NEEDED.

It tells me exactly what the logic but it seems so incredible that this error is in a book like this. I need a confirmation, there will be this freaking.

Thank soo much in advance for your comments.

ADDED AT USER Rohan REQUEST:

What's difference in 2 lines? Make question more clear. – Rohan 33 mins ago.

ANSWER to Rohan:

Hello and Thanks to question. In C

x = 5 is used to assign to the variable x the value 5, for example.

However, if what you want is to check the equality symbol is correct ==

if x == 5 Say if x is equal to 5 ...

As you can see the book are assigning c = '\t'

which makes no sense and was giving me errors

"If c is equal to tab" is if (c == '\t') Where \t are the TAB key.

I hope I have clarified some doubt

And thanks for asking

You can check http://www.tutorialspoint.com/cprogramming/c_operators.htm

Where you can see:

== Checks if the values of two operands are equal or not, if yes then condition becomes true.

(A == B) is not true.

Upvotes: 1

Views: 726

Answers (1)

dandan78
dandan78

Reputation: 13854

Yes, you are correct in your assessment that the = needs to be replaced with a ==.

Typos happen, even in books and even in K&R.

However, you mention that you copied the code straight from a PDF. That PDF was likely OCRed from a book and OCR software is far from perfect, so mistakes can do happen.

Upvotes: 1

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