KwCheng's blog

Sometimes , we may want to find word in string.

we can use string::find to achieve this purpose.

int main()

{

string str = "This is a book";

string word = "book";

int found = str.find(word);

if(found !=string::nops)

{

cout<<"Congratulation!! we find the word , book."<<endl;

} 

else

{

cout<<"This word is not exist!!"<<endl;

} 

return 0;

} 

string::nops的定義如下:

static const size_t nops = -1;

一般來說 , nops昰定義為 -1 , 代表的是greatest possible value .

但因為size_t昰 unsigned integral type , 所以若定義為size_t , 那麼他會return largest representative value.

string::find()

if we find the word in the string , find() will return the position in string of the word or find() will return nops.