Question

我试图“显示前50个甚至斐波纳契数字的总和”，目前输出错误。

我需要：

创建一个生成斐波那契数字的循环。
测试每一个是偶数还是奇数。
添加偶数，计算它们。

我是JavaScript的新手，无法让我的代码工作。非常感谢任何帮助/指导。他们是一个更好，更简单的方式吗？

------------这是我的代码，因为--------

<div id="sumFib" class="hwbutton">Get the Sum!</div><br>

The sum of the first 50 even Fibonacci numbers is: <span class="" id="sumFibResult"></span>
<br>

<script type="text/javascript">
var getFibSum = document.getElementById("sumFib");
getFibSum.onclick = function(){
fiftyEvenFibonacciSum();
 }

function fiftyEvenFibonacciSum(){

var loopFib;

//Initialize fibonacci array

var fibonacci = new Array();

//Add fibonacci array items
fibonacci[0] = 0;
fibonacci[1] = 1;
var sum=0;

//Since it takes 150 fib numbers to obtain 50 even, loop through that many.
for(loopFib=2; loopFib<=150; loopFib++) {

    // Next fibonacci number = previous + one before previous
    fibonacci[loopFib] = fibonacci[loopFib-2] + fibonacci[loopFib-1];

    //test for even numbers with if then statement
    var integer = parseInt(fibonacci[loopFib]);

    if (integer % 2 == 0) {

    //Add up the even fib numbers if even and output into dispay variable
    var display = sum += fibonacci[loopFib];

    //output results to html page
    document.getElementById("sumFibResult").innerHTML = display ;

}
}
}
</script>

Answer 1

试试这个我添加了一个计数器来阻止在达到50之后添加偶数的执行，让我知道是否有效

    var fibonacci = new Array();

//Add fibonacci array items
fibonacci[0] = 0;
fibonacci[1] = 1;
var sum=0;

//Since it takes 150 fib numbers to obtain 50 even, loop through that many.
var counter=0;
for(loopFib=2; loopFib<=150; loopFib++) {

    // Next fibonacci number = previous + one before previous
    fibonacci[loopFib] = fibonacci[loopFib-2] + fibonacci[loopFib-1];

    //test for even numbers with if then statement
    var integer = parseInt(fibonacci[loopFib]);

    if (integer % 2 == 0  && counter < 50) {
        counter++;
        //Add up the even fib numbers if even and output into dispay variable
        var display = sum += fibonacci[loopFib];
    //console.log(fibonacci[loopFib]);   //output results to html page
            //console.log(counter);  
        document.getElementById("sumFibResult").innerHTML = display ;

}
}

Answer 2

这就是我的做法。

let num = 1;
let sum = 0;
let counter = 0;

function evenCheck(x)
{
    if(x%2===0)
    {
        return true;
    }
return false;
}

for(let i=0; i<1000; i+=num)
{
    num += i;
    if(counter>=50)
    {
        break;
    }
    if(evenCheck(i))
    {
        sum += i;
        counter++;
    }
    if(evenCheck(num))
    {
        sum += num;
        counter++;
    }
}
console.log(sum);

Javascript循环通过Fibonacci数字并测试偶数

2 个答案: