JavaScript中while循环经典例题1

1. 九九乘法表

//css样式
<style type="text/css">
			table{
				border-collapse:collapse;
			}
			td{
				border:1px solid blue;
				text-align: center;
				color: darkolivegreen;
				font-size: 20px;
				padding: 10px 10px;
				
			}
		</style>

//代码
		var row = 1;
		document.write("<table border = 1px>");
		while(row <= 9){
			document.write("<tr>");
			var col = 1;
			
			while(col <= row){
				document.write("<td>");
				document.write(row + "*" + col + "=" + row * col);
				col++;
				document.write("</td>");
			}
			
			document.write("<br />");
			document.write("</tr>");
			row++;
		}
		document.write("</table>");

2.     *
    	**
    	***
    	****
    	*****
   

打印以上图案

var star = "*";
			var row = 1;
			while(row <= 5){
				var col = 1;
				while(col <= row){
					document.write(star);
					col++;
				}
				document.write("<br />");
				row++;
			}

3. 求0000-20220所有 平年 + 所有闰年

			var year1 = 0000;
			var count1 = 0;//计数普通闰年
			var count2 = 0;//计数世纪闰年
			
			while(year1 <= 2020){
				if(year1 % 4 == 0 && year1 % 100 != 0){
					console.log(year1 + "为普通闰年");
					count1++;
				}else if(year1 % 400 == 0){
					console.log(year1 + "为世纪闰年");
					count2++;
				}
				year1++;
			}
			console.log(count1);
			console.log(count2);		

4. 1-100奇偶数求和

			var num = 1;
			var sum = 0;
			var odd = 0; //奇数
			
			while(num <= 100){
				if(num % 2 == 1){
					console.log(num + "是奇数");
					odd = odd + num;
				}else{
					console.log(num + "是偶数");
					sum = sum + num;
				}
				
				num++;
			}
			

5. 操场大约一百多人,三个三个排剩一个,四个四个排剩二个,五个五个排剩二个;

			var num = 100;
			var flag = true;
			while(flag){
				if(num % 3 == 1 && num % 4 == 2 && num % 5 == 2){											
					console.log(num);
					flag = false;
				}
				num++;
			}

6. 猜拳

		var success = 0;
		var lose = 0;
		while (success < 2 && lose < 2 ){
			var player = prompt("请输入你的猜拳");
			if(player != "" && player != null){
				var computer = Math.floor(Math.random() * 3);
				switch (computer){
					case 0:
						computer = "剪刀";
						break;
					case 1:
						computer = "石头";
						break;
					case 2:
						computer = "布";
						break;
				}
				console.log("computer = " + computer);
				if(player == computer){
					console.log("平局")
				}else if (player == "剪刀" && computer == 2 || player == "石头" && computer == 0 || player == "布" && computer == 3){
					console.log("玩家赢");
					success++;
				}else{
					console.log("电脑赢");
					lose++;
				}
			}else{
				console.log("输入有误");
			}
			
		}
		console.log(success);
		if(success == 2){
			console.log("玩家取得最终胜利");
		}else{
			console.log("电脑取得最终胜利");
		}

7. 水箱装水120立方，水龙头每小时进水12立方，每小时出水30立方，问：多少小时排完？

		var hour = 0;
		var water = 120;
		
		while(water > 0){
			hour++; 
			//water = 120 - (30 - 12) * hour;//我一开始的想法，思路没错，但是最好不要这样写
			water += 18; 
			water -= 30;
			
		}
		console.log(hour);

8. 甲乙丙丁四个人加工零件 加工的总零件数为370个
   如果甲加工的零件数多10
   如果已加工的零件数少20
   如果丙加工的零件数乘以2
   如果丁加工的零件数除以2
   则四个人加工的零件数就相等 （//设为ave）
   求四个人加工的零件个数分别是多少

		var ave = 0;//Ave是四个人运算后相同的零件数
	  	while(true){
	  		if((ave - 10) + (ave + 20) + (ave / 2) + (ave * 2) == 370){
	  			console.log("甲 = " + ave - 10);
	  			console.log("乙 = " + ave + 20);
	  			console.log("丙 = " + ave / 2);
	  			console.log("丁 = " + ave * 2);
	  			break;
	  		}else{
	  			ave++; 
	  		}
	  	}

9. 100元换零钱，有50元，20元、10元、5元、1元

		var x = 0;//50元
	  	var count1 = 0;//计数一共多少种方法
	  	while(x <= 2){
	  		var y = 0;//20元
	  		while(y <= 5){
	  			var z = 0;//10元
	  			while(z <= 10){
	  				var w = 0;//5元
	  				while(w <= 20){
	  					var o = 0;//1元
	  					while(o <= 100){
	  						if(50 * x + 20 * y + 10 * z + w * 5 + 1 * o == 100){
	  						console.log(x, y, z, w, o);
	  						count1++;
	  						}
	  						o++;
	  					}
	  					w++;
	  				}
	  				z++;
	  			}
	  			y++;
	  		}
	  		x++;
	  	}
	  	 
	  	console.log(count1); 

10.计算100-999之间的水仙花数

		var num = 100;
	  	while(num <= 999){
	  		var handred = Math.floor(num / 100);
		  	var ten = Math.floor(num % 100 / 10);
		  	var indeviual = Math.floor(num % 10);
	  		if(num == handred ** 3 + ten ** 3 + indeviual ** 3){
	  			
	  			console.log(num);
	  		}
	  		num++;
	  	} 

11. 图一：
    
    图二：
    

			var line = 6;//行
			if(line == 6){
				document.write("⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐");
				line -= 1;
			}
			document.write("<br />");//line = 5;
			while(line >  0){//line >= 0时 0也会进入empty循环，会输出11个月亮，即图二，而正确的输出结果应该是图一
				var col = 1;//列
				while (col <= line){
					document.write("⭐");
					col++;
				}
				var empty = 0;
				while(empty < 2 * (5 - line + 1) - 1 ){
					document.write("????");
					empty++;
				}
				
				var col1 = 1;
				while (col1 <= line){
					document.write("⭐");
					col1++;
				}
				document.write("<br />");
				line--;
			}