利用JavaScript打印出Fibonacci数（不使用全局变量打印斐波那契数）

outputFibonacci(20);

function outputFibonacci(lenght){
return function Fibonacci(arrays,len){
if(typeof len!=='number'||len<=1){
document.write(len);
return;
}
if(arrays.length==0){
arrays[0]=0;
arrays[1]=1;
Fibonacci(arrays,len);
}
else if(arrays.length<=len){
arrays.push(arrays[arrays.length-1]+arrays[arrays.length-2]);
Fibonacci(arrays,len);
}
else{
document.write(arrays[len]);
}
}([],lenght);
}

function outputFibonacci(n){
return n<2?n:outputFibonacci(n-1)+outputFibonacci(n-2)
}

function outputFibonacci(n){
var memo=[0,1];
var fib = function (n){
var result=memo
;
if(typeof result!=='number'){
result=fib(n-1)+fib(n-2);
memo
=result;
}
return result;
};
return fib;
}

outputFibonacci()(20);