Tuesday, January 19, 2010

JavaScript Arrays: Pushing, Popping and Shifting

1) Merge of Join Two array:

it's quite easy

var a=new Array('a','b','c');
var b=new Array('d','e','f');
var c=a.concat(b);

c will be an array: ('a','b','c','d','e','f').



 2) : Pushing, Popping and Shifting
<script  id="clientEventHandlersJS"  language="javascript">
<!--
functionShow()
{
      var myArray = new Array();
      myArray[0] = "Jag";
      myArray[1] = "Chat";
      myArray[2] = "Win";
      myArray[3] = "Dhan";
      document.write("Before adding
-------------
");
      for (var i = 0; i < myArray.length; i++)
      {
            document.write(myArray[i] + "
");
      }
      myArray.push("aaa");
      document.write("
After adding
-------------
");
      for (var i = 0; i < myArray.length; i++)
      {
            document.write(myArray[i] + "
");
      }
}

function ButtonPush_onclick() {
      Show();
}



the result:
When the above code is executed we get the following output:
Before adding
-------------
Red
Green
Blue
White

After adding
-------------
Red
Green
Blue
White
aaa
3)

3) copying, transferring and merging

functionShow()
{
      var SimpleString = "abc;def;ghi;jkl;mno;qrs";
      var myArray = SimpleString.split(";");
      var subArray = myArray.slice(0,3);
      document.write("first array
---------
");
      for (var i = 0; i < myArray.length; i++)
      {
            document.write(myArray[i] + "
");
      }
      document.write("
second array
---------
");
      for (var i = 0; i < subArray.length; i++)
      {
            document.write(subArray[i] + "
");
      }
}

JavaScript arrays: copying, transferring and merging - How to copy the elements of one array into another using JavaScript: discussion

(Page 2 of 5 )

Within the code I showed you in the previous section, I mainly created a simple button (which is identified as “Button1”).  The button is defined with an “onclick” event which calls a JavaScript function, “Button1_onclick.”  The same function simply calls another JavaScript function named “Show.”

The function “Show” is defined as follows:

functionShow()

{

      var SimpleString = "abc;def;ghi;jkl;mno;qrs";

      var myArray = SimpleString.split(";");

      var subArray = myArray.slice(0,3);

      document.write("first array
---------
");

      for (var i = 0; i < myArray.length; i++)

      {

            document.write(myArray[i] + "
");

      }

      document.write("
second array
---------
");

      for (var i = 0; i < subArray.length; i++)

      {

            document.write(subArray[i] + "
");

      }

}

In the above code fragment, I worked with a sample string as follows:

      var SimpleString = "abc;def;ghi;jkl;mno;qrs";

From the above statement, we can easily determine that the “separator” for the elements would be “;” or semi-colon (as explained in my second article in this series).  Proceeding further we have the following:

      var myArray = SimpleString.split(";");

The above statement makes the string split into several elements, based on the separator “;” (semi-colon).  Once the splitting is completed, it creates an array of those elements and assigns the same to the variable “myArray.” Continuing on, we have the following:

      var subArray = myArray.slice(0,3);

The above statement creates a new array with only three elements (copied from  the 0th location or index) from the main array “myArray” and finally assigns the same to “subArray.”

We use the following loop to display all the elements (as explained in my first article):

      for (var i = 0; i < subArray.length; i++)

      {

            document.write(subArray[i] + "
");

      }

I also displayed the elements available in the first array using the following loop:

      for (var i = 0; i < myArray.length; i++)

      {

            document.write(myArray[i] + "
");

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