C++ STRING FUNCTIONS:

We can still use all the functions present in C Language  <string.h> library as including <cstring> and make use of all its string handling functions.

The string is an object of std::string class in c++. It provides many of the in-built functions that can be used with the strings without including any library.

These are some of the functions present in string class.

In this article, we are going to learn about the string class functions and implement some of them with examples.

C++ String Compare():

This function compares the value of the string object to the sequence of characters specified by its parameter.

SYNTAX:

Suppose these are two strings and we would like to compare them. This function returns an integer value based on the comparison.

int k= str1.compare(str2);  

• k==0 : If k contains value zero, it means both the strings are equal.
• k!=0 : If k does contain value zero, it means both the strings are unequal.
• k>0 : If k contains value more than zero, either the value of the first character is greater in the compared string or all the compared characters match but the compared string is longer.
• k<0 : If k contains value less than zero, either the value of the first character is lower in the compared string or all the compared characters match but the compared string is shorter.

Let us look at an example to implement this function:

#include<iostream>  
using namespace std;  
void main()  
{  
   string str1="Hello";  
   string str2="inprogrammer";  
    int k= str1.compare(str2);  
    if(k==0)  
         cout<<"Both the strings are equal";  
     else  
       cout<<"Both the strings are unequal";  
  
}  

OUTPUT

Both the strings are not equal

C++ String length()

This function is used to find the length of the string in terms of bytes.

Syntax:

int len = s1.length(); 

This function returns the length of the string specified.

Let’s look at an example:

#include<iostream>  
using  namespace std;  
int main()  
{  
string s1 = "Welcome to inprogrammer";  
int len = s1.length();  
cout<< "length of the string is : " << len;  
return 0;  
}   

OUTPUT

Length of the string is 23

C++ string push_back():

This function is used to add one character at the end of the string and increases its length by one.

Let’s see an example:

#include<iostream>  
using namespace std;  
            int main()  
           {  
           string s1 = "Hell";  
           cout<< "String is :" <<s1<<'\n';  
           s1.push_back('o');  
           cout<<"Now, string is :"<<s1;  
          return 0;     
           }   

OUTPUT

String is Hell
Now, string is Hello

C++ string pop_back():

This function is used to remove one character from the end of the string and decreases its length by one.

Let’s see an example:

#include<iostream>  
using namespace std;  
            int main()  
           {  
           string s1 = "Hello";  
           cout<< "String is :" <<s1<<'\n';  
           s1.pop_back();  
           cout<<"Now, string is :"<<s1;  
          return 0;     
           }   

OUTPUT

String is Hello
Now, string is Hell

C++ String copy():

copy() function in c++ is used to copy the contents from one string to another.

Syntax

Source_string.copy(dest_string, length, position);

Let us look at an example:

#include<iostream>  
using namespace std;  
int main()  
{  
string str = "java programs";  
char str1[13] ;  
str.copy(str1,8,5);  
str1[8] ='\0';  
cout<<"String contains : " <<str1;  
return 0;   
} 

OUTPUT

String contains programs

CONCLUSION:

Hurray! You have successfully learned the concepts of strings in c++. To master this concept, do some exercises on strings. Happy Coding 🙂