An in depth discussion of JavaScript Arrays - Working with single dimensional arrays: discussion
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Within the code 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”, which is defined as follows:
function Button1_onclick() {
Show();
}
The above function simply calls another JavaScript function named “Show.” The function “Show” is defined as follows:
function Show()
{
var myArray = new Array();
myArray[0] = "Jag";
myArray[1] = "Chat";
myArray[2] = "Win";
myArray[3] = "Dhan";
for (var i = 0; i < myArray.length; i++)
{
document.write(myArray[i] + "<BR>");
}
}
Let us discuss the above function part by part.
var myArray = new Array();
The above statement creates an array named “myArray.” “Array()” is a built-in definition available in the JavaScript language. You can create as many named arrays as possible (within a single web page).
myArray[0] = "Jag";
myArray[1] = "Chat";
myArray[2] = "Win";
myArray[3] = "Dhan";
To place values (or data) in an array, we need to specify the position (or index) within the array. The first statement in the above fragment simply places a value “Jag” (of type string) into the first position or index (identified by 0). Similarly, “chat” is placed in second position (identified by 1) and so on. Now, let us go through the last part:
for (var i = 0; i < myArray.length; i++)
{
document.write(myArray[i] + "<BR>");
}
To display all the values in an array, we need to know the number of values available (or occupied) in an array. This can be achieved by using the “length” property of any array object. Within the above loop, we go through every position (or index) in an array starting from the first location (or 0th index) and proceeding through the last (using the “length” property).
Finally we write back to the browser using “document.write”. Within “document.write” we specify the array name along with the index (so that the value at that index gets retrieved), concatenated together with the “<BR>” tag for line separation.
Next: Working with two dimensional arrays >>
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