Learn Blus teacher JS (2)--Deep JavaScript

1. Function parameters

variable parameter (indeterminate parameter): variable number of arguments parameters, example of parameter array 1. Sum of all parameters

<! DOCTYPE html>functionsum () {//alert (arguments.length);    //alert (arguments[0]);    //arguments        varResult=0;  for(vari=0;i<arguments.length;i++) {result+=Arguments[i]; }        returnresult;} Alert (SUM (12, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6, 8, 6));</script>View CodeExample 2:css function to judge arguments.length parameter name, enhance readability
<! DOCTYPE html>functioncss (obj, name, value) {if(arguments.length==2)//Get    {        returnObj.style[name]; }    Else                    //Set{Obj.style[name]=value; }}window.onload=function (){    varOdiv=document.getelementbyid (' Div1 '); Alert (CSS (Odiv,' Width ')); //css (odiv, ' background ', ' green ');};</script>View Code
2. Take non-inline styles:
Take a non-inline style (cannot be used to set):
OBJ.CURRENTSTYLE[ATTR]//iegetcomputedstyle (obj, false) [attr]//chrome/ff
<! DOCTYPE html>#div1 {width:200px; height:200px; background:red;}</style><script>functionGetStyle (obj, name) {if(Obj.currentstyle)//IE    {        returnObj.currentstyle[name]; }    Else                                    //Chrome/ff    {        returngetComputedStyle (obj,false) [name]; }}window.onload=function (){    varOdiv=document.getelementbyid (' Div1 '); Alert (GetStyle (Odiv,' BackgroundColor '));};</script>View Code
But pay attention to the above getstyle () problems, this can only take a single style, if you want to take a compound style, such as the above background, to use the ' backgroundcolor '
3. Array Basics
1) adding, deleting elements
Add to
 
   

  
    
 
     
Push (Element), added from tail
 
    
 
   
 
   

  
    
 
     
Unshift (Element), added from the head
 
    
 
   
Delete
 
   

  
    
 
     
Pop (), pops up from the tail
 
    
 
   
 
   

  
    
 
     
Shift (), pops up from the head
 
    
 
   
2) Insert, delete
Splicesplice (start, length, element ...) First Delete, then insert
 
   

  
    
 
     
Delete
 
    
 
   
Splice (start, length)
 
   

  
    
 
     
Insert
 
    
 
   
Splice (start, 0, element ...)
 
   

  
    
 
     
Replace
 
    
 
   
<script>var arr=[1,2,3,4,5,6]; // Delete: Splice (start, length) // Arr.splice (2, 3); // Insert: Splice (beginning, length, element ...); // Arr.splice (2, 0, ' A ', ' B ', ' C '); Arr.splice (2, 2, ' A ', ' B '); alert (arr); </script>
View Code
3) Sort, convert
Sort
 
   

  
    
 
     
Sort ([comparison function]), sorting an array
 
    
 
   
Sort a string array sort a numeric array transformation class
 
   

  
    
 
     
Concat (array 2)
 
    
 
   
Connect two arrays
 
   

  
    
 
     
Join (delimiter)
 
    
 
   
Use delimiters, combine array elements, generate string string split
<script>var arr=[' float ', ' width ', ' alpha ', ' zoom ', ' left '];arr.sort (arr) ; </script>
View Code
<script>var , 8, arr=[12,];arr.sort (  N1, n2) {      return n1-n2;     /* if (n1<n2)    {        return-1;    }    else if (n1>n2)    {        return 1;    }    else    {        return 0;    } */ }); alert (arr); </script>
View Code
4.
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Learn Blus teacher JS (2)--Deep JavaScript