计算100的阶乘

计算100的阶乘

    <script>
        let product = 1;
        for (let num = 1; num <= 100; num++) {
            product *= num;				//累乘100次
        }
        console.log(product);
    </script>

计算1！+2！+3！+…+20！

    <script>
        let sum = 0;
        for (let q = 1; q <= 20; q++) {		//外层循环累加
            let product = 1;		
            for (let i = 1; i <= q; i++) {	//内层循环累积，且令i的值小于等于外层的q，做到递增
                product *= i;
            }
            sum += product;
        } 
		console.log(sum);
    </script>