利用js模拟银行系统
<script>
var card = 100;
var flag = true;
while(flag){
var option = prompt("银行存取管理\n1.存钱\n2.取钱\n3.查询余额\n4.退出系统");
switch (option) {
case '1':card += +prompt("输入您需要存入金额：");break;
case '2':card -= +prompt("输入您取出的金额：");break;
case '3':alert("您当前余额是："+card);break;
case '4':flag = false;break;
default: alert("选择项"+option+"不存在");
}
}
</script>
数组处理
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>数组</title>
<script>
function fun_arr_1(){
console.log("数组反转练习")
var list = ["1","2","3","4","5"];
console.log("初始数据",list);
var len = list.length;
for (var i = 0; i < len / 2; i++){ //
var temp = list[i]; //list[4]
list[i] = list[len - 1 - i];
list[len - 1 - i]= temp;
}
console.log("反转后数据",list);
}
function fun_arr_2(){
console.log("\n数组求和练习")
var num = prompt("请输入班级人数：");
var scores = [];
var sum = 0;
for (var i = 0; i < num; i++){
scores[i] = prompt("输入第"+(i+1)+"位学生成绩");
sum += +scores[i];
}
var max = scores[0];
var min = scores[0];
for (var i = 1; i < scores.length; i++){
if (scores[i] > max){
max = scores[i];
}else if (scores[i] < min){
min = scores[i];
}
}
console.log("总成绩", sum);
console.log("平均分", sum/+num);
console.log("最高分", max);
console.log("最低分", min);
}
function fun_arr_3(){
console.log("\n数组求和去除最高最低练习")
var scores = [];
var sum = 0;
for (var i = 0; i < 10; i++){
scores[i] = prompt("输入第"+(i+1)+"位评委评分成绩");
sum += +scores[i];
}
var max = scores[0];
var min = scores[0];
for (var i = 1; i < scores.length; i++){
if (scores[i] > max){
max = scores[i];
}else if (scores[i] < min){
min = scores[i];
}
}
console.log("平均分", (sum - max - min)/10);
console.log("最高分", max);
console.log("最低分", min);
}
function fun_arr_4() {
var arr = [10, 20, 10, 30, 40, 50, 30];
var new_arr = [];
console.log(arr);
/*//方式一
var flag = new Array(arr.length);
for (var i = 0; i < arr.length; i++){
var temp = arr[i];
if (!flag[i]) {
new_arr[new_arr.length] = arr[i];
//重复标记
for (var j = i+1; j < arr.length; j++){
if ( !flag[j] && temp === arr[j]){
flag[j] = true;
}
}
}
}*/
//方式二
for (var i = 0; i < arr.length; i++){
var flag = false;
for (var j = 0 ; j < new_arr.length; j++){
if (new_arr[j] === arr[i]){
flag = true;
}
}
if (!flag){
new_arr[new_arr.length] = arr[i];
}
}
console.log(new_arr);
}
function fun_arr_5(){
var arr = new Array(10);
for (var i = 0; i < 10; i++){
arr[i] = "";
}
for (var i = 0; i < 10; i++){
for (var j = 0; j < 10; j++){
if (i == j || i == 10 - j - 1){
document.write("<b>o</b>");
arr[i] += "o";
} else {
document.write("<b>*</b>");
arr[i] += "*";
}
}
arr[i] += "\n";
document.write("<br/>");
}
console.log(arr);
}
</script>
</head>
<body>
<button οnclick="fun_arr_1();">数组反转</button>
<button οnclick="fun_arr_2();">成绩统计</button>
<button οnclick="fun_arr_3();">歌唱评分</button>
<button οnclick="fun_arr_4();">数组去重</button>
<button οnclick="fun_arr_5();">二维数组</button>
</body>
</html>
函数
function getNowTime() {
//根据时间对象获取方法
var date = new Date();
//获取年份
var year = date.getFullYear();
//获取月份
var month = date.getMonth() + 1;
//获取第几天
var day = date.getDate();
//获取小时
var hours = date.getHours();
//获取分钟
var minutes = date.getMinutes();
//获取秒数
var seconds = date.getSeconds();
//格式化日期
return year+"-"+month+"-"+day+" "+hours+":"+minutes+":"+seconds;
}
对象
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>对象</title>
<script>
function fun_rand(){
//Math对象直接调用属性或方法
//0~1随机数，坐闭右开
var rand_num = Math.random();
console.log("[0,1)随机数", rand_num);
//
var num = rand_num*10;
console.log("[0,10)随机数", num);
//四舍五入
var round_num = Math.round(num);
console.log("四舍五入", round_num);
//向上/下取整
var up_num = Math.ceil(num);
var down_num = Math.floor(num);
console.log("向上取整",up_num);
console.log("向下取整",down_num);
//注意负数的四舍五入
console.log(Math.round(-11.6)); //-12，舍去
console.log(Math.round(-11.2)); //-11，进一
}
function fun_rand_game() {
//随机数获取索引
var foods = ["烤山药", "烤番薯", "榨菜", "馒头", "方便面", "地沟油"];
var index = Math.round(Math.random()*(foods.length-1));
console.log("今天中午你吃", foods[index]);
}
function fun_rand_game1() {
var rand_num = Math.ceil(Math.random()*100);
while (true){
var result = prompt("请输入1~100的整数");
//console.log(result, rand_num);
if (result == rand_num){
alert("恭喜你猜中了！！！");
break;
}else if(result > rand_num){
alert("猜大了");
}else if(result < rand_num){
alert("猜小了");
}
}
}
</script>
</head>
<body>
<button οnclick="fun_rand()">Math用法</button>
<button οnclick="fun_rand_game()">随机食物</button>
<button οnclick="fun_rand_game1()">猜数字游戏</button>
</body>
</html>
