C++ program to find length of string

C++ program to find length of string. Here I have given four methods to find length of string like using strlen() function, without using strlen() function, using recursion, using pointer.

Method 1 : C++ program to find length of a string without using strlen() function

#include<iostream>
#include<conio.h>
#include<string.h>
using namespace std;
int main()
{
    char str[20];
    int i;
    cout<<"Enter String : ";
    cin>>str;
    for(i=0;str[i]!='\0';i++);
    cout<<"Length of string is : "<<i;
    return 0;
}

Method 2 : C++ program to find length of a string using strlen() function

#include<iostream>
#include<conio.h>
#include<string.h>
using namespace std;
int main()
{
    char temp,str[50];
    int lenght;
    cout<<"Enter String : ";
    cin>>str;
    lenght=strlen(str);
    cout<<"Length of string is : "<<lenght;
    return 0;
}

Method 3 : C++ program to find length of a string using pointer

#include<iostream>
using namespace std;
int main()
{
    char str1[20],*p;
    int i;
    cout<<"Enter string : ";
    cin>>str1;
    p=str1;
    for(i=0;*p!='\0';i++,p++);
    cout<<"Length of string : "<<i;
    return 0;
}

Method 4 : C++ program to find length of a string using recursion

#include<iostream>
using namespace std;
int lenght(char *str,int i)
{
    if(str[i]=='\0')
        return i;
    else
       return lenght(str,i+1);
}
int main()
{
    char str[50];
    cout<<"Enter string : ";
    cin>>str;
    cout<<"Length of string : "<<lenght(str,0);
    return 0;
}