Fibonacci Sequence

fibonacci.js

//Normal

function fibonacci(number) {

  if (number > -1) {
    var arr = [];

    for (var i=0; i<=number; i++){
      if (i==0){
        arr.push(0);
      } else if (i==1){
        arr.push(1);
      } else {
        arr.push(arr[i-1] + arr[i-2]);
      }
    }

    return(arr[number]);

  } else {

    return undefined;

  }

}

fibonacci(5);



//CodeEval

var fs  = require("fs");

fs.readFileSync(process.argv[2]).toString().split('\n').forEach(function (line) {
  if (line !== "") {
    fibonacci(line);
  }
});

function fibonacci(number) {

  var numberCheck = parseInt(number, 10);

  if (numberCheck > -1) {
    var arr = [];

    for (var i=0; i<=numberCheck; i++){
      if (i===0){
          arr.push(0);
      } else if (i==1){
          arr.push(1);
      } else {
          arr.push(arr[i-1] + arr[i-2]);
      }
    }

    return (arr[numberCheck]);

  } else {
    return undefined;
  }

}