使用Javascript找到最大的素数因子

Question

谢谢阅读.一般来说,Javascript和编程都是新手.

我正在寻找一种方法来返回给定数字的最大素数因子.我的第一直觉是使用while循环来计算并查找数字的素数因子,将因子存储在数组中并在每次找到时重置.这样,数组中的最后一项应该是最大的素数因子.

var primerizer = function(input){
    var factors = [];
    var numStorage = input
    for (x=2; numStorage != 1; x++){            // counter stops when the divisor is equal to the last number in the 
                                                // array, meaning the input has been fully factorized
        if (result === 0) {                     // check if the number is prime; if it is not prime
            factors.push(x);                    // add the divisor to the array of prime numbers
            numStorage = numStorage/x           // divide the number being calculated by the divisor
            x=2                                 // reset the divisor to 2 and continue
        };
    };
    primeFactor = factors.pop();
    return primeFactor;
}


document.write(primerizer(50))

这只返回2,未定义或没有.我担心for循环的停止条件必须根据与开始条件相同的变量来定义,所以我尝试使用while循环.

 var primerizer = function(input){
    var factors = [];
    var numStorage = input
    x=2
    while (numStorage != 1){
        var result = numStorage%x;
        if (result === 0) {
            factors.push(x);
            numStorage = numStorage/x
            x=2
        }
        else {
            x = x+1
        }
    }
    return factors.pop();
}
document.write(primerizer(50)

同样的问题.也许我的语法存在问题,我忽略了？任何输入都非常感谢.

谢谢.

Answer 1

我找到的最短答案是:

function largestPrimeFactor(n){
var i=2;
while (i<=n){
    if (n%i == 0){
        n/=i;    
    }else{
        i++;
    }
}
console.log(i);
}
var a = **TYPE YOUR NUMBER HERE**; 
largestPrimeFactor(a)