Find length of a string.

//Program to find length of a string.
#include<conio.h>
#include<iostream.h>
#include<stdio.h>

void main()
{
    clrscr();
    char a[80];
    cout<<"Enter a string: ";
    gets(a);
    for(int i=0;a[i]!='\0';i++);
    cout<<"The length of the string is: "<<i;
    getch();
}