The find_first_of()
function is available in the <algorithm>
library in C++. This function is used to find the location of the first occurrence of any of the specified characters in a string.
The following is the function prototype.
size_t find_first_of (const string& str, size_t pos = 0) const;
The find_first_of()
method takes the following parameters:
String or Character (str
): The string or character containing the characters to be searched.
Position (pos
): This specifies the starting position for the search. By default, this is set to 0
.
The function returns the position of the first occurrence of the character(s) in the specified string/character. If no matches are found, the function returns string::npos
.
You can read more about
string::npos
here.
Let’s have a look at the code.
#include<iostream>using namespace std;int main(){string s1 = "I got first position and she stood below the first position";string s2 = "Programming";cout << "Original string:" << s1<< endl;// returns 4 as 't' from 'first' is identified at the 4th index (got)cout << "Position of the first occurrence of the string 'first' is " << s1.find_first_of("first", 1) << endl;cout << "Original string:" << s2 << endl;// returns 3 as 'g' from 'Programming' is identified at the 3rd indexcout << "Position of the first occurrence of the character 'g' is " << s2.find_first_of('g', 2);return 0;}
In line 1, we import the required header files.
In line 3, we make a main()
function.
In lines 6 and 7, we initialize two variables of string type.
In line 8, we display the first original string.
In line 9, we use the find_first_of()
function to get the position of the first occurrence of the specified string and the starting position for search and display it with a message.
In line 10, we display the second original string.
In line 11, we use the find_first_of()
function to get the position of the first occurrence of the specified character in the string and the starting position for search and display it with a message.
In this way, we can use the find_first_of()
to find the position of the first occurrence of the character of a specified string or character.