Question

Hi everyone, I have a problem about C programming.

Background Material：

we'll consider only strings that are made using character codes from the ASCII character set, which is listed as a table in Figure 6. ASCII is reasonably good for text in English, but is obviously not at all adequate for text in most other human languages. It's possible in C to manage strings that could contain any characters from any written language, but that's an advanced topic Most of Figure 6 is self-explanatory, but there are a few things about it that could use a little extra explanation . The codes corresponding to decimal number from 0 up to and including 31, and also 127, are called control characters. Most of them have very little use in modern computing, but some of them are very important, such as 0 the null character, 9-the tab character, 10-the newline character, and a few others. The table shows how to represent character 92, the backslash character, as a C character constant. Here is how to write a single quote as a character constant: On a somewhat related note, here is how to insert double quotes into a string constant: "I'd like to say "Hello!\" to my friends!

The figure 6 is as below:

The task:

Download the file 55.c. Study the C code, then build an executable and run it to see what the output is. Modify the program so that the output is The string in buffer is "In C the value of 12 + 34 / 5 is 18." Do this by looking up decimal values for ASCII codes in Figure 6 and typing them into the .c file as necessary—in this exercise you’re not allowed to add character constants or string constants to the C code.

The answer:

The printout of complete code of 55.c

Below is the file 55.c:

#include <stdio.h>

int main(void)
{
  char buffer[80];   // enough space for a string of length <= 79

  // THIS IS A GOOD WAY TO LEARN SOMETHING ABOUT C STRINGS, BUT IT'S
  // NOT A GOOD EXAMPLE OF READABLE OR PRACTICAL CODE! 

  // Put characters into the string using ASCII codes.
  buffer[0] = 84;
  buffer[1] = 104;
  buffer[2] = 105;
  buffer[3] = 115;
  buffer[4] = 32;
  buffer[5] = 105;
  buffer[6] = 115;
  buffer[7] = 32;
  buffer[8] = 69;
  buffer[9] = 78;
  buffer[10] = 67;
  buffer[11] = 77;
  buffer[12] = 32;
  buffer[13] = 51;
  buffer[14] = 51;
  buffer[15] = 53;
  buffer[16] = 33;
  buffer[17] = 0;

  // Put the end-of-string character at the end of the string.
  buffer[17] = 0;

  printf("The string in buffer is \"%s\"\n", buffer);
  return 0;
}

Answer 1

If you have any doubts, please give me comment...

Output is: The string in buffer is "This is ENCM 335!"

Modified program:

#include <stdio.h>

int main(void)

{

char buffer[80]; // enough space for a string of length <= 79

// THIS IS A GOOD WAY TO LEARN SOMETHING ABOUT C STRINGS, BUT IT'S

// NOT A GOOD EXAMPLE OF READABLE OR PRACTICAL CODE!

// Put characters into the string using ASCII codes.

buffer[0] = 73;

buffer[1] = 110;

buffer[2] = 32;

buffer[3] = 67;

buffer[4] = 32;

buffer[5] = 116;

buffer[6] = 104;

buffer[7] = 101;

buffer[8] = 32;

buffer[9] = 118;

buffer[10] = 97;

buffer[11] = 108;

buffer[12] = 117;

buffer[13] = 101;

buffer[14] = 32;

buffer[15] = 111;

buffer[16] = 102;

buffer[17] = 32;

buffer[18] = 49;

buffer[19] = 50;

buffer[20] = 32;

buffer[21] = 43;

buffer[22] = 32;

buffer[23] = 51;

buffer[24] = 52;

buffer[25] = 32;

buffer[26] = 47;

buffer[27] = 32;

buffer[28] = 53;

buffer[29] = 32;

buffer[30] = 105;

buffer[31] = 115;

buffer[32] = 32;

buffer[33] = 49;

buffer[34] = 56;

buffer[35] = 46;

// Put the end-of-string character at the end of the string.

buffer[36] = 0;

printf("The string in buffer is \"%s\"\n", buffer);

return 0;

}