天恒娱乐注册:js常用数组操作方法简明总结

标签:网站展示    日期:2018-02-09 14:52    录入:天恒娱乐平台注册    浏览:

  

[js,数组操作,简明总结]js常用数组操作方法简明总结

  
  
  //javascript 中的数组分割  var colors = ["red","green","blue"];  //alert(colors.toString());  alert(colors.join("|")); //返回结果是red|green|blue  var colors = ["red","green","blue",null];  alert(colors.join("|"));//red|green|blue|  //注意当数组里面有值是null或者是undefined的时候 返回的结果是以空的字符串表示的  -------------------------------------------  //数组删除和添加  var colors = ["red","green","blue"];  //alert(colors.toString());  colors.push("white","test");//返回的结果是数组的长度  alert(colors.join("|"));//结果是red|green|blue|white|test  //往数组的开头添加元素  var colors = ["red","green","blue","test"];  var item = colors.unshift("first");//数组的开头添加一个元素  alert(colors.join("|"));//返回最后的数组  //删除元素  var colors = ["red","green","blue","test"];  var item = colors.pop();//返回删除的选项结果test  alert(colors.join("|"));//返回最后的数组结果red|green|blue  //删除开头元素  var colors = ["red","green","blue","test"];  var item = colors.shift();//删除数组的第一个选项  alert(colors.join("|"));//返回最后的数组  -------------------------------------------------  //数组顺序事例  //顺序颠倒  var colors = ["red","green","blue","test"];  colors.reverse();  alert(colors);//结果是:test,blue,green,red  //数组排序  var values = [0,1,5,10,7];  values.sort(compare);  alert(values);  //document.writeln(values);  }  function compare(value1,value2){  if(value1value2){  return -1 ;  }else return 0 ;  }  -----------------------------------------------------  //向天恒娱乐注册数组中添加数组 concat()方法  var colors = ["color","red"];  var colors2 = colors.concat(["ccc","bbbb"],'3333',['vvccxx',['oolll','lll']]);  alert(colors2);//返回结果是:color,red,ccc,bbbb,3333,vvccxx,oolll,lll  //slice()方法复制数组中的元素并不会破坏之前的元素  var colors = ["color","red",'eeee','221111'];  var colors2 = colors.slice(1);//从1开始进行复制  alert(colors2);//结果是:red,eeee,221111  var colors = ["color","red",'eeee','221111'];  var colors2 = colors.slice(1,3);//从1开始进行复制到第3个位置结束  alert(colors2);//结果是red,eeee  ---------------------------------------------------------------------  //数组中删除元素  var a = [1,2,3,5,8];  var r = a.splice(0,2); //删除前2项  alert(a);//结果是3,5,8  var a = [1,2,3,5,8];  var r = a.splice(1,1,100,200); //从第2个数开始删除一项 然后插入100 200  alert(a);//结果是1,100,200,3,5,8
  
  

  

★★★小编:天恒娱乐 整理文章,欢迎大家转载 ★★★