Easy tutorial for C / C ++ - string 2 ('>>' operator, cin.get(), strlen() functions)

Easy tutorial for C / C ++ - string 2 ('>>' operator, cin.get(), strlen() functions)

strlen() :

- A function to determine the length of a string. To use the strlen () function, you need to include the string.h header file. That is, you need to write #include <string.h> in your code.

- Let's look at an example that takes the length of a string input through cin. To get a string, we use the '>>' operator of the cin object and the 'get ()' method to see the difference.

Example Code

#include <iostream>

#include <string.h>

using namespace std;

int main() {

     char Tst_1[255] ;

     char Tst_2[255] ;

     int LenS ;

     cout << "Using \'>>\' operator" << endl ;

     cout << "Enter a string. : " ;

     cin >> Tst_1 ;

     LenS = strlen(Tst_1);

     cout << " Tst_1         = " << Tst_1 << endl ;

     cout << " strlen(Tst_1) = " << LenS << endl ;

     cout << endl ;

     cin.ignore(255,'\n');

     cout << "Using \'cin.get()\' method" << endl ;

     cout << "Enter a string. : " ;

     cin.get(Tst_2,255) ;

     LenS = strlen(Tst_2);

     cout << " Tst_2         = " << Tst_2 << endl ;

     cout << " strlen(Tst_2) = " << LenS << endl ;

     cin.ignore(255,'\n');

     return 0;

}

- String arrays 'Tst_1' and 'Tst_2' were defined to store the string. And we declared an integer variable 'LenS' to store the length of the string.

- First, we wrote the code for receiving input using '>>' operator. After input, we will assign the length of the input string to 'LenS'. We will then print the contents and length of the string.

- To empty the string stored in the buffer, we use the command 'cin.ignore (255,' \ n ');' And thus the next data can be read from the keyboard.

- We have written the code for receiving input using 'cin.get ()' method. We will then input the string and print the contents and length of the string.

results :

Using '>>' operator

Enter a string. :

- You will be prompted to enter a string. Type "abcd efgh" and hit enter.

Using '>>' operator

Enter a string. : abcd efgh

 Tst_1      = abcd

 strlen(Tst_1) = 4

Using 'cin.get()' method

Enter a string. :

- As a result, only "abcd" is output and the length of the string is '4'. If you use the '>>' operator to input characters with the space character, this space character is regared as the end of the string. And the characters after it are not stored in the variable. Therefore, only the "abcd" will be saved and the length will be 4.

- In the input method using 'cin.get ()' method, input "abcd efgh" and press enter.

Using '>>' operator

Enter a string. : abcd efgh

 Tst_1         = abcd

 strlen(Tst_1) = 4

Using 'cin.get()' method

Enter a string. : abcd efgh

 Tst_2         = abcd efgh

 strlen(Tst_2) = 9

- You can see that the input "abcd efgh" is correctly printed. And the length of the string is 9. (Including the space bar)