此函数用于查找指定字符首次出现的位置。
find_first_of - 语法
str1.find_first_of(str);
find_first_of - 参数
str - 包含要搜索的字符的字符串。
pos - 它定义开始搜索的位置。
n - 标识要搜索的字符的字符数。
ch - 它定义了要搜索的字符
find_first_of - 返回值
它返回搜索字符的位置。
find_first_of - 例子1
让我们看一个简单的例子。
#include<iostream> using namespace std; int main() { string str1 = "Dancing is my favorite hobby"; cout << "String contains :"<< str1<< ; cout <<"Position of the first occurrence of the string favorite is " << str1.find_first_of("favorite"); return 0; }
输出:
String contains : Dancing is my favorite hobby Position of the first occurrence of the string favorite is 1
find_first_of - 例子2
让我们看一个简单的示例，其中指定了开始搜索的位置。
#include<iostream> using namespace std; int main() { string str = "Welcome to the programming world"; cout<< "String contains : "<< str << ; cout<<"Now, start the search from the second position and we find the first occurrence of the programming is :"<<str.find_first_of("programming",2); return 0; }
输出:
String contains : Welcome to the programming world Now, start the search from the second position and we find the first occurrence of the programming is : 4
find_first_of - 例子3
让我们看一个简单的示例，查找单个字符首次出现的位置。
#include<iostream> using namespace std; int main() { string str = "learnfk tutorial"; cout << "String contains :" << str<< ; cout <<"Position of the first occurrence of a character is :" << str.find_first_of(a); return 0; }
输出:
String contains learnfk tutorial Position of the first occurrence of a character is : 1
