• javascript学习笔记(六):对象、内置对象


    创建对象

    对象属性赋值的方式

     1 <!DOCTYPE html>
     2 <html>
     3 <head lang="en">
     4     <meta chaset="UTF-8">
     5     <title></title>            
     6 </head>    
     7 <body>
     8     <script>
     9         people = new Object();     //javascript对象的创建
    10         
    11         //对people对象属性赋值第一种方式
    12         people.name = "jerry";      //对people对象的name属性赋值
    13         people.age = "18";           //对people对象的age属性赋值
    14         document.write("name:"+people.name+",age:"+people.age+"</br>");
    15         
    16         //对people对象属性赋值第二种方式
    17         people = {name:"tom",age:"15"};//对people对象的name属性、age属性赋值
    18         document.write("name:"+people.name+",age:"+people.age);
    19 
    20     </script>
    21 </body>
    22 </html>

    创建自定义对象

     1 <!DOCTYPE html>
     2 <html>
     3 <head lang="en">
     4     <meta chaset="UTF-8">
     5     <title></title>            
     6 </head>    
     7 <body>
     8     <script>
     9         //自定义对象的创建
    10         //使用函数来创建对象,然后创建对象实例
    11         function people(name,age){
    12             this.name = name;
    13             this.age = age;
    14         }
    15         son = new people("tom",30);
    16         document.write("name:"+son.name+",age:"+son.age);
    17     </script>
    18 </body>
    19 </html>

    javascript内置对象

    string对象

     1 <!DOCTYPE html>
     2 <html>
     3 <head lang="en">
     4     <meta chaset="UTF-8">
     5     <title></title>            
     6 </head>    
     7 <body>
     8     <script>
     9         var str = "Hello World";
    10         document.write("字符串长度:"+str.length+"</br>");
    11         document.write("查询字符串的位置:"+str.indexOf("World")+"</br>");
    12         document.write("匹配字符串是否存在,若存在输出这个字符,若不存在输出空:"+str.match("World")+"</br>")
    13         document.write("替换字符串:",str.replace("World","javascript")+"</br>");
    14         document.write("字符串转换成大写:"+str.toUpperCase()+"</br>");
    15         document.write("字符串转换成小写:"+str.toLowerCase()+"</br></br>");
    16         
    17         var str1 = "Hello,tom,jerry,gophi";
    18         document.write("字符串:"+str1+"</br>");
    19         var s = str1.split(",");
    20         document.write("字符串分割之后的结果:</br>");
    21         document.write(s[0]+"</br>");
    22         document.write(s[1]+"</br>");        
    23         document.write(s[2]+"</br>");
    24         document.write(s[3]+"</br>");    
    25     </script>
    26 </body>
    27 </html>

    date对象

     1 <!DOCTYPE html>
     2 <html>
     3 <head lang="en">
     4     <meta chaset="UTF-8">
     5     <title></title>            
     6 </head>    
     7 <body>
     8     <script>
     9         var date = new Date();
    10         document.write("时间:"+date+"</br>");       //获取时间总信息
    11         document.write(+date.getFullYear()+"年</br>");  //获取年份
    12         document.write("星期"+date.getDay()+"</br>");   //获取星期几
    13         document.write("时间戳:"+date.getTime()+"</br>");//获取时间戳
    14         date.setFullYear(2000,1,1)             //设置时间
    15         document.write("设置时间为:"+date+"</br>");    //获取时间总信息        
    16     </script>
    17 </body>
    18 </html>

    一个简单的时钟程序

     1 <!DOCTYPE html>
     2 <html>
     3 <head lang="en">
     4     <meta chaset="UTF-8">
     5     <title></title>            
     6 </head>    
     7 <body onload="startTime()"> <!--用一个onload事件调用startTime函数-->
     8     <script>
     9         function startTime(){
    10             var today = new Date();
    11             var h = today.getHours();    //获取时
    12             var m = today.getMinutes();    //获取分
    13             var s = today.getSeconds(); //获取秒
    14             m = checkTime(m);
    15             s = checkTime(s);
    16             
    17             document.getElementById("timetxt").innerHTML = h+":"+m+":"+s;
    18             t = setTimeout(function(){startTime();},1000);      //每1000毫秒刷新一次时间
    19             //checkTime函数的作用是使分、秒为个位数时仍输出两位,比如9分5秒,输出09:05                
    20         }
    21         function checkTime(i){
    22             if(i<10){
    23                 i = "0" + i;
    24             }
    25             return i;
    26         }
    27     </script>
    28     <div id="timetxt"></div>            <!--设置一个显示时间的标签-->    
    29 </body>
    30 </html>

    array对象

     1 <!DOCTYPE html>
     2 <html>
     3 <head lang="en">
     4     <meta chaset="UTF-8">
     5     <title></title>            
     6 </head>    
     7 <body> 
     8     <script>
     9         //concat():合并数组
    10         var a=["hello","world"];
    11         var b=["tom","jerry"];
    12         var c=a.concat(b);
    13         document.write(c+"</br>");
    14         
    15         //sort():排序
    16         var aa=["a","e","c","v","b"];
    17         document.write(aa.sort()+"</br>");
    18         
    19         var bb=[1,9,2,3,4,7,8,5];
    20         document.write(bb.sort()+"</br>");
    21         
    22         //push():末尾追加元素
    23         var cc=["a","b"];
    24         cc.push("c");
    25         document.write(cc+"</br>");
    26         
    27         //reverse():数组元素翻转
    28         var dd=["1","2","3","4","5"];
    29         document.write(dd.reverse());
    30         
    31     </script>        
    32 </body>
    33 </html>

    math对象

     1 <!DOCTYPE html>
     2 <html>
     3 <head lang="en">
     4     <meta chaset="UTF-8">
     5     <title></title>            
     6 </head>    
     7 <body> 
     8     <script>
     9         //round(),四舍五入
    10         document.write(Math.round(2.5)+"</br>");
    11         //random(),0~1之间的随机数        
    12         document.write(Math.random()+"</br>");
    13         //parseInt(),取整
    14         document.write(parseInt(Math.random()*10)+"</br>");//求0~10之间的随机整数
    15         //max(),求最大值
    16         document.write(Math.max(10,2000,1,35,6.7,-10)+"</br>");
    17         //min(),求最小值
    18         document.write(Math.min(10,2000,1,35,6.7,-10)+"</br>");
    19         //abs(),求绝对值
    20         document.write(Math.abs(-10));
    21     </script>        
    22 </body>
    23 </html>
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  • 原文地址:https://www.cnblogs.com/zylq-blog/p/7002235.html
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