Strings (Example 1)

Concepts:
String and library functions for their manipulation (library string.h)

Text:
Implements a C program that:

• declares three strings (i.e., arrays of characters), str1 and str2 of dimension N e str3 whose dimension is obtaining directly during its initialization.
• prints str3
• acquires a string in str1
• copy str1 in str2
• prints str2
• prints the length of str2
• reduces the dimension of str2 writing the character '\0' in place of the fourth character of str2
• prints the new obtained string str2
• compares the content of str1 and str2, printing if they are equal or different

Solution:

string_1.c

/*
  Example about the utilization of strings and the string.h library
*/
 
#include <stdio.h>
#include <string.h>
 
#define N 20
 
int main(){
  char str1[N], str2[N], str3[]="abc";
 
  printf("STR3 : %s\n", str3);
 
  /*scanf("%s", str1);*/ /* Read only a word */
  gets(str1); /* Read the whole line */
  printf("STR1 : %s\n", str1);
 
  strcpy(str2, str1); /* Copy the content of str1 in str2 */
  printf("STR2 : %s\n", str2);
  printf("LEN  : %d\n", (int)strlen(str2)); /* strlen returns the length of a string */
 
  str2[3] = '\0'; /* Writes the end-of-string character '\0' in the position number 3 of the array of character. The string is truncated at position 2 (the resulting string is therefore formed by only 3 characters) */
  printf("STR2b: %s\n", str2 );
 
  if (strcmp(str1, str2)==0){ /* The function strcmp returns 0 if the two strings are equals, a value other than 0 if they are different (<0 if str1 is less than str2, >0 if str1 is greater than str2 */ 
    printf("str1 is equal to str2\n");
  }else{
    printf("str1 different from str2\n");
  }
 
  return 0;
}