zoukankan      html  css  js  c++  java
  • javascript常用对象

    1.Date对象:

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
     <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
    <script type="text/javascript">
      var date = new Date();
      document.write(date);
    </script>
     </head>
     <body>
     </body>
    </html>
    


    运行结果:

    我们来改变一下输出的方式:

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
     <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
    <script type="text/javascript">
      var date = new Date();
      document.write(date.getFullYear()+"年"+date.getMonth()+"月"+date.getDate()+"日");
    </script>
     </head>
     <body>
     </body>
    </html>


    运行结果:

    明明是9月,却显示的是8月,说明getMonth是从下标0开始的,所以要加1:

     document.write(date.getFullYear()+"年"+(date.getMonth()+1)+"月"+date.getDate()+"日");


    这样就会输出正确的结果了。

    2.String对象:

    2.1

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
     <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
    <script type="text/javascript">
      var str1 = new String("niujiabin");
      var str2 = "niujiabin";
      alert(str1==str2);
    </script>
     </head>
     <body>
     </body>
    </html>
    


    结果是true,这里与java是有区别的,并不存在引用,没有equals方法。

    2.2字符串连接

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
    <script type="text/javascript">
      var str1 = new String("niujiabin");
      var str2 = "niujiabin";
    //  alert(str1==str2);
    //字符串的连接
    var str3 = str2.concat("maybe","gossip");
    alert(str3);
    </script>
    </head>
    <body>
    </body>
    </html>


    连接字符串,concat的参数没有限制,随便连就可以了,输出结果:

    2.3字符串截取

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
     <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
      <script type="text/javascript">
    //字符串截取
    var str1 = "niujiabinbin";
    var str2 = str1.slice(3,6);
    alert(str2);
    </script>
     </head>
    
     <body>
      
     </body>
    </html>
    


    运行结果:

    2.4字符串选取substring与substr

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
     <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
      <script type="text/javascript">
       var str1 = "niujiabinbin";
       document.write(str1.substring(2,9)+"<br>");
       document.write(str1.substr(2,9));
    </script>
     </head>
    
     <body>
      
     </body>
    </html>
    


    运行结果:

    区别在于substring是下标2-9,而substr是从下标2开始,选取9个字符。

    3.array对象:

    js中的array对象其实就是java中的List和Stack集合

    3.1

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
     <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
      <script type="text/javascript">
      //第一种定义方式
      var a1 =new Array();
      a1.push(11);
      a1.push(12);
      document.write(a1+"<br>");
    
      //第二种定义方式
      var a2 = new Array("niujiabin","1",1);
      document.write(a2+"<br>");
       
      //第三种定义方式,一般都采用这种方式
      var a3=["maybe",1,"1"];
      document.write(a3+"<br>");
    </script>
     </head>
     <body>  
     </body>
    </html>
    


    输出结果:

    输出结果的分割形式都是逗号,我们当然也可以改变,只需通过join方法:

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
     <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
      <script type="text/javascript">
      //第一种定义方式
      var a1 =new Array();
      a1.push(11);
      a1.push(12);
      document.write(a1.join("-")+"<br>");
    
      //第二种定义方式
      var a2 = new Array("niujiabin","1",1);
      document.write(a2.join("_")+"<br>");
       
      //第三种定义方式,一般都采用这种方式
      var a3=["maybe",1,"1"];
      document.write(a3.join("***")+"<br>");
    </script>
     </head>
     <body>  
     </body>
    </html>
    


    运行结果:

    3.2 sort方法:

    这个方法只会根据字符串来排序:

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
     <head>
      <title> New Document </title>
      <meta name="Generator" content="EditPlus">
      <meta name="Author" content="">
      <meta name="Keywords" content="">
      <meta name="Description" content="">
      <script type="text/javascript">
    
      var a3=[1111,111,12,443,44,555,5555,67,76];
      document.write(a3.sort());
    </script>
     </head>
     <body>  
     </body>
    </html>
    


    排序结果:

    array的方法还有pop,shift,onshift等对栈和队列的相关操作,还有splice插入元素,这里就不一一介绍了。

  • 相关阅读:
    python全栈学习--day48
    python全栈学习--day47(HTML-----高级选择器与盒子模型等
    python全栈学习--day46(html---列表,标签,表格,表单,css引入与基本选择器)
    python-面向对象编程设计与开发
    python-知识点的复习2
    python-知识点的复习
    python-re模块
    python-logging模块
    python-hash和md5算法
    python-配置文件的处理configpasser模块
  • 原文地址:https://www.cnblogs.com/riskyer/p/3323119.html
Copyright © 2011-2022 走看看