C + + String and its comparison with char[]

Before I learned C + +, I usually learned the language.

In the C language we save the string using char[]

But the use of string is more frequent in C + + than char[] The following is a little bit of my understanding of string

1. As with other standard library types, a user program needs to use a string type object to contain the associated header file (to provide an appropriate using declaration for easy authoring)

#include <string>using std::string;

Definition and initialization of 2.string objects

    string s1;//Creating an empty    string  string s2 ("wo yao ac");//create strings with an initial value of wo yao    ac s2string S3 (S2);//Create S2 copy   s3 Value change  does not affect S2    string S4 (2,'A  ');//Create a String S4   value of 2 characters ' a    'string s5=s2+s3;//Create a string S5   value of S2+S3

The output result is

3.string Reading and writing

In c we use the following two methods to read into the string

scanf ("%s", S1);
Gets (S1);

In C + +, the read-in method used for string-type data is CIN

cin>>s1;

Reading and ignoring the beginning of the whitespace character reads the string to resemble scanf ("%s", S1) until it encounters a white-space character again;

But when it comes to solving the problem, we can't just save contiguous non-empty characters.

At this time we need a reading method like Get (Getline) (CIN,S1);

Operation of 4.string objects

    S1.empty ();   // to determine if S1   is null is to return true   not to return false    s2.size ();    // returns the number    of characters in S2 S1[i];   // returns the character    that is labeled I in S1 S1+S2;  // returns a string  whose value is equal to S1 followed by S2    s1=s2;   // pay the value of S2 to S1

C + + String and its comparison with char[]