How to write a C Program to find Last Occurrence of a Character in a String with an example?.
C Program to find Last Occurrence of a Character in a String Example 1
This program allows the user to enter a string (or character array), and a character value. Next, it will search and find the last occurrence of a character inside a string using If Else Statement.
/* Find Last Occurrence of a Character in a String */
#include <stdio.h>
#include <string.h>
int main()
{
char str[100], ch;
int i, index;
index = -1;
printf("\n Please Enter any String : ");
gets(str);
printf("\n Please Enter the Character that you want to Search for : ");
scanf("%c", &ch);
for(i = 0; i <= strlen(str); i++)
{
if(str[i] == ch)
{
index = i;
}
}
if(index == -1)
{
printf("\n Sorry!! We haven't found the the Search Element '%c' ", ch);
}
else
{
printf("\n The Last Occurrence of the Search Element '%c'' at Position %d ", ch, index + 1);
}
return 0;
}
First, we used C For Loop to iterate each character in a C String.
for(i = 0; i <= strlen(str); i++)
{
if(str[i] == ch)
{
index = i;
}
}
str[] = Hello World
ch = l
Index = -1
C While Loop First Iteration: while (str[ i ] != 0)
The condition is True because str[0] = H.
Within the C Programming While Loop, we used C If statement to check whether the str[0] is equal to a user-specified character or not
if(str[i] == ch) => if(H == l)
The above condition is false. So, i will increment, and the Index value is still -1.
Second Iteration: while (str[ 1 ] != 0)
The condition is True because str[1] = e.
if(str[i] == ch) => if(e == l) – condition is false. So, i value will be incremented, and Index value is still -1.
Third Iteration: while (str[ 2 ] != 0) – condition is True because str[2] = l.
if(str[i] == ch) => if(l == l) – condition is True.
Index = i
index = 2
Third Iteration: while (str[ 3 ] != 0) – condition is True because str[3] = l.
if(str[i] == ch) => if(l == l) – condition is True.
index = i = 3
Do the same for remaining iterations.
Next, we used the C If Else Statement to check the index value is equal to -1. Here, the condition is False. So, the statement inside the else block will execute.
printf("\n The Last Occurrence of the Search Element '%c' is at Position %d ", ch, i + 1);
Here, i is the index position (start with zero), and i + 1 is the actual position.
C Program to find Last Occurrence of a Character in a String Example 2
This C program for last character occurrence is the same as above. Here, we just replaced the For Loop with a While Loop.
#include <stdio.h>
#include <string.h>
int main()
{
char str[100], ch;
int i, index;
i = 0;
index = -1;
printf("\n Please Enter any String : ");
gets(str);
printf("\n Please Enter the Character that you want to Search for : ");
scanf("%c", &ch);
while(str[i] != '\0')
{
if(str[i] == ch)
{
index = i;
}
i++;
}
if(index == -1)
{
printf("\n Sorry!! We haven't found the the Search Element '%c' ", ch);
}
else
{
printf("\n The Last Occurrence of the Search Element '%c'' at Position %d ", ch, index + 1);
}
return 0;
}
Please Enter any String : tutorial gateway
Please Enter the Character that you want to Search for : a
The Last Occurrence of the Search Element 'a'' at Position 15C Program to find Last Occurrence of a Character in a String Example 3
This C program for last Character occurrence is the same as the first example, but this time we used the C Functions concept to separate the logic.
#include <stdio.h>
#include <string.h>
int Find_LastCharcater(char str[], char ch);
int main()
{
char str[100], ch;
int index;
printf("\n Please Enter any String : ");
gets(str);
printf("\n Please Enter the Character that you want to Search for : ");
scanf("%c", &ch);
index = Find_LastCharcater(str, ch);
if(index == -1)
{
printf("\n Sorry!! We haven't found the Search Character '%c' ", ch);
}
else
{
printf("\n The Last Occurrence of the Search Element '%c' at Position %d ", ch, index + 1);
}
return 0;
}
int Find_LastCharcater(char str[], char ch)
{
int i, index;
index = -1;
for(i = 0; str[i] != '\0'; i++)
{
if(str[i] == ch)
{
index = i;
}
}
return index;
}
Please Enter any String : learn c programming
Please Enter the Character that you want to Search for : n
The Last Occurrence of the Search Element 'n' at Position 18 C Program to find Last Occurrence of a Character in a String Example 4
This C program is same as the first example, but this time we are using the C pointers concept.
/* Fnd Last Occurrence of a Character in a String */
#include <stdio.h>
#include <string.h>
int Find_LastCharcater(char *str, char ch);
int main()
{
char str[100], ch;
int index;
printf("\n Please Enter any String : ");
gets(str);
printf("\n Please Enter the Character that you want to Search for : ");
scanf("%c", &ch);
index = Find_LastCharcater(str, ch);
if(index == -1)
{
printf("\n Sorry!! We haven't found the Search Character '%c' ", ch);
}
else
{
printf("\n The Last Occurrence of the Search Element '%c' at Position %d ", ch, index + 1);
}
return 0;
}
int Find_LastCharcater(char *str, char ch)
{
int i, index;
i = 0;
index = -1;
while(*str)
{
if(*str == ch)
{
index = i;
}
i++;
str++;
}
return index;
}
Please Enter any String : welcome to tutorial gateway
Please Enter the Character that you want to Search for : e
The Last Occurrence of the Search Element 'e' at Position 24 Also Read