fibonacci number

The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, 
starting from 0 and 1. That is,
F(0) = 0, F(1) = 1
F(n) = F(n - 1) + F(n - 2), for n > 1.
Given n, calculate F(n).

class Solution {
    public int fib(int n) {
       if(n<=1){
           return n;
       }
       int []fib_arr=new int [n+1];
       fib_arr[1]=1;
       for(int i=2;i<=n;i++){
           fib_arr[i]=fib_arr[i-1]+fib_arr[i-2];
       }
       return fib_arr[n]; 
    }
}