Example:
Input string: I love programming.
Input character: o
Output: 3
Required knowledge
Basic C programming, If else, Loop, StringProgram to find first occurrence of character in string
/** * C program to find the first occurrence of a character in a string */ #include <stdio.h> #include <string.h> #define MAX_SIZE 100 /** Function declaration */ int indexOf(const char * text, const char toFind); int main() { char text[MAX_SIZE]; char toFind; int index; /* * Reads a string from user and character to be searched */ printf("Enter any string: "); gets(text); printf("Enter character to be searched: "); toFind = getchar(); index = indexOf(text, toFind); if(index == -1) { printf("'%c' not found.", toFind); } else { printf("Index of '%c' is %d.", toFind, index); } return 0; } /** * Returns the first index of the given character toFind in the string. * If returns -1 if the given character toFind does not exists in the string. */ int indexOf(const char * text, const char toFind) { int index = -1; // Assumes that the character doesn't exists int i, len; len = strlen(text); for(i=0; i<len; i++) { if(text[i] == toFind) { index = i; break; } } return index; }
Output
Enter any string: I love programming.
Enter character to be searched: o
Index of 'o' is 3.
Enter character to be searched: o
Index of 'o' is 3.
Note: Index returned by the function indexOf() is zero based index.
Happy coding ;)
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