Javascript Interview Question Number Get Fibonacci number without recursion

Introduction

Write an iterative method to generate nth Fibonacci number.

F(n) = F(n-1) + F(n-1); F(0) == 0, F(1) == 1; 

function fibonacci(n) {
    //your code here
}

console.log( fibonacci(99) );//from   w  ww .j a  va 2  s.  c om

/*
Output: ($ /usr/bin/node 011.js)
218922995834555200000
*/




function fibonacci(n) {
    if (n === 0) {
        return 0;
    }

    if (n === 1) {
        return 1;
    }

    if (n < 1) {
        return -1;
    }

    var i = 0;
    var c = 0;
    var a = 1;
    var b = 1;

    for (i = 3; i <= n; i++) {
        c = a + b;
        a = b;
        b = c;
    }

    return b;
}

console.log( fibonacci(99) );

/*
Output: ($ /usr/bin/node 011.js)
218922995834555200000
*/



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