String Data Structure - Learnengineeringforu

 String Data Structure

Strings are defined as an array of characters. The difference between a character array and a string is the string is terminated with a special character ‘\0’.

Declaring a string is as simple as declaring a one dimensional array. Below is the basic syntax for declaring a string in C programming language.

char str_name[size];

Function to copy string (Iterative and Recursive)

Given two strings, copy one string to other using recursion. We basically need to write our own recursive version of strcpy in C/C++

Examples:

Input : s1 = "hello"
        s2 = "Learnengineeringforu"
Output : s2 = "hello"

Input :  s1 = "Learnengineeringforu"
         s2 = ""
Output : s2 = "Learnengineeringforu"

Iterative : 

Copy every character from s1 to s2 starting from index = 0 and in each call increase the index by 1 until s1 doesn’t reach to end;

// Iterative CPP Program to copy one String   // to another. #include <bits/stdc++.h> using namespace std;    // Function to copy one string to other // assuming that other string has enough // space. void myCopy(char s1[], char s2[]) {     int i = 0;     for (i=0; s1[i] != '\0'; i++)        s2[i] = s1[i];     s2[i] = '\0'; }    // Driver function int main() {     char s1[100] = "Learnengineeringforu";     char s2[100] = "";     myCopy(s1, s2);     cout << s2;     return 0; }

Output:

Learnengineeringforu

Recursive : 

Copy every character from s1 to s2 starting from index = 0 and in each call increase the index by 1 until s1 doesn’t reach to end;

// CPP Program to copy one String to  // another using Recursion #include <bits/stdc++.h> using namespace std;    // Function to copy one string in to other // using recursion void myCopy(char s1[], char s2[], int index = 0) {     // copying each character from s1 to s2     s2[index] = s1[index];         // if string reach to end then stop      if (s1[index] == '\0')           return;        // increase character index by one     myCopy(s1, s2, index + 1);  }    // Driver function int main() {     char s1[100] = "Learnengineeringforu";     char s2[100] = "";     myCopy(s1, s2);     cout << s2;     return 0; }

Output:

Learnengineeringforu