es6函数之尾递归用法实例分析

function factorial(n) {
 if (n === 1) return 1
 return n  factorial(n - 1)
}

function factorial(n, total = 1) {
if (n === 1) return total
return factorial(n - 1, n  total)
}

factorial(5)

function Fibonai (n) {
 if ( n <= 1 ) {return 1};

 return Fibonai(n - 1) + Fibonai(n - 2);
}

Fibonai(10) // 89
Fibonai(100) // 堆栈溢出
Fibonai(500) // 堆栈溢出

function Fibonai2 (n , ac1 = 1 , ac2 = 1) {
 if( n <= 1 ) {return ac2};

 return Fibonai2 (n - 1, ac2, ac1 + ac2);
}

Fibonai2(100) // 573147844013817200000
Fibonai2(1000) // 7.0330367711422765e+208
Fibonai2(10000) // Infinity

function currying(fn, n) {
return function(m) {
return fn.call(this, m, n)
}
}