C++ Strings

    A String is a one-dimensional array of character data types which ends with a null value represented by '\0'. The array of character always terminates with a null value, so if there is a character array(string) of size 6 and it has only 5 elements filled, so the 6 th place would be a null value.

    To initialize a string

    There are two techniques by which we can initialize a string:

    char string[10]={'t','e','c','h','g','e','e','k'};


    char string[10]="techgeek";

    string[10] value stored as:

    |t|e|c|h|g|e|e|k|'\0'| |

    Note: The string should always reside in double quotes “ ”.

    'a' Vs "a" (Character Vs String)

    If any value is inside single quotes then it considered as a Character in C++ and if its inside double quote it considerer String: So here 'a' represent a single character and, "a" represents string. Example

    #include <iostream>
    using namespace std;  
    int main()
         char ch = 'T', string[20]= "TechGeekBuzz";
         cout<<"The value ch store is: "<<ch;
         cout<<"The value string store is: "<<string;
         return 0;              

    Output The value ch store is: T The value string store is: TechGeekBuzz Behind the code Here ch and string belong to the same data type char, but both represent different data structure. ch is a character data type whereas string is a character array data structure. That’s why ch is only able to store one character and string is able to store 20 characters.

    C++ in-built String Function

    C++ has a string library that contains some C++ string in-built functions. To use these string functions we need to mention the header file name of the string function, which is <#include string.h> .

    String Function Description
    strcpy( str1 , str2 ); Copy the value of string str2 into string str1
    strcat( str1 , str2 ); Concatenate string str2 with string str1 . Join the value of str2 in str1
    strlen( str1 ); It returns the total number of characters present in the string.
    strcmp( str1 , str2 ); It compares str2 with str1 , and return 0 if str1 and str2 are same, returns less than 0 if str1 is smaller than str2 and return greater than 0 if str1 is greater than str2 .
    strchr( str1 , ch); It returns the pointer to the first occurrence of character ch in the string str1 .
    strstr( str1 , str2 ); Returns a pointer to the first occurrence of string str2 in string str1 .


    #include <iostream>
    using namespace std;
    int main()
          char str1[10]="tech", str2[10]="geek", str3[10], ch='t';      
          strcpy(str3,str1); // copy the value of str1 into str3
          cout<<"The value of str3: "<<str3;
         cout<<"The value of strcat(str1, str2) is: "<<strcat(str1,str2); //add the value of str2 in str1
         cout<<"The length of str2 is: "<<strlen(str2); // print the length of str2


    The value of str3: tech 
    The value of strcat(str1, str2) is: techgeek 
    The length of str2 is: 4

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