Given a string calculate length of the string using recursion.
Examples:
Input : str = "abcd" Output :4 Input : str = "GEEKSFORGEEKS" Output :13
We have discussed 5 Different methods to find length of a string in C++
How to find length of a string without string.h and loop in C?
Algorithm:
recLen(str) { If str is NULL return 0 Else return 1 + recLen(str + 1) }
Implementation:
C++
// CPP program to calculate length of // a string using recursion #include <bits/stdc++.h> using namespace std;
/* Function to calculate length */ int recLen( char * str)
{ // if we reach at the end of the string
if (*str == '\0' )
return 0;
else
return 1 + recLen(str + 1);
} /* Driver program to test above function */ int main()
{ char str[] = "GeeksforGeeks" ;
cout << recLen(str);
return 0;
} |
Java
// java program to calculate length of // a string using recursion import java.util.*;
public class GFG{
/* Function to calculate length */
private static int recLen(String str)
{
// if we reach at the end of the string
if (str.equals( "" ))
return 0 ;
else
return recLen(str.substring( 1 )) + 1 ;
}
/* Driver program to test above function */
public static void main(String[] args)
{
String str = "GeeksforGeeks" ;
System.out.println(recLen(str));
}
} // This code is contributed by Sam007. |
Python3
# Python program to calculate # length of a string using # recursion str = "GeeksforGeeks"
# Function to # calculate length def string_length( str ) :
# if we reach at the
# end of the string
if str = = '':
return 0
else :
return 1 + string_length( str [ 1 :])
# Driver Code print (string_length( str ))
# This code is contributed by # Prabhjeet |
C#
// C# program to calculate length of // a string using recursion using System;
public class GFG{
/* Function to calculate length */
private static int recLen( string str)
{
// if we reach at the end of the string
if (str.Equals( "" ))
return 0;
else
return recLen(str.Substring(1)) + 1;
}
/* Driver program to test above function */
public static void Main()
{
string str = "GeeksforGeeks" ;
Console.WriteLine(recLen(str));
}
} // This code is contributed by vt_m. |
PHP
<?php // PHP program to calculate // length of a string using // recursion // Function to // calculate length function recLen(& $str , $i )
{ // if we reach at the
// end of the string
if ( $i == strlen ( $str ))
return 0;
else
return 1 +
recLen( $str ,
$i + 1);
} // Driver Code $str = "GeeksforGeeks" ;
echo (recLen( $str , 0));
// This code is contributed by // Manish Shaw(manishshaw1) ?> |
Javascript
<script> // JavaScript program to calculate length of // a string using recursion /* Function to calculate length */ function recLen(str)
{
// if we reach at the end of the string
if (str == "" )
return 0;
else
return recLen(str.substring(1)) + 1;
}
// Driver code let str = "GeeksforGeeks" ;
document.write(recLen(str));
</script> |
Output
13
Time Complexity : O(n)
Auxiliary Space : O(n) for recursion call stack.
Since this solution requires extra space and function call overhead, it is not recommended to use it in practice.
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