分解质数因子

var m,b,c=0,j=0;
var arr=[];
function fjzys(k){

var i = 2;
while(k>=i) {
if (k%i == 0) {
arr[j] = i;
k/=i;
i=2;
j++;
} else {
i++;
}
}

}

fjzys(100); //求100的质数因子

for(var b = 0; b<(j-1); b++) {
console.log(arr[b]);
console.log('*');
}

console.log(arr[j-1]);

var num = prompt('input your number then i will go on:','90');
var regex = new RegExp(/^[0-9]*[1-9][0-9]*$/);
var i = 2;
var handle = num;
var arr = new Array();
while(i<handle){        //i小于num则一直循环下去，直到i=num为止
var result = handle/i;
if(regex.test(result)){    //除2结果为整数
arr.push(i);
i=2;
handle=result;
}else{
i++;
}
if(i == handle-1){    //判断是否要结尾
arr.push(handle)
break;
}
}
//打印结果
var str = String();
for(i=0;i<arr.length;i++){
str += arr[i];
if(i != arr.length-1)
str += '*';
}
alert('the result :'+str);