Page 79 - DCAP202_Fundamentals of Web Programming

Fundamentals of Web Programming

Notes  Objects contain properties and methods;
 Arrays contain a sequential list of elements;
Functions contain a collection of statements.

Task Compare and contrast primitive data types and composite data types.

Self Assessment

Fill in the blanks:
11. .......................... data types are the types that can be assigned a single literal value.

12. .......................... are rows of characters enclosed in either double or single quotes.

6.7 Creating Values

Here, we will demonstrate the use of JavaScript for accessing the values of form elements.

6.7.1 Value for Text Input Element

Figure 6.3: Text Input Element

To obtain a reference to a text input element, here is some sample code:
oText = oForm.elements[“text_element_name”]; OR
oText = oForm.elements[index];
In the code above, "index" is the position of the element in the 0-based elements array, and
oForm is the form object reference obtained using the document.forms collection:
oForm = document.forms[index];
To get the value of the text input element, we can use the value property of the text input object:
text_val = oText.value;
As an example, if we have the following text input element:
<input type="text" name="name" id="txt_name" size="30" maxlength="70">
We can access the value of the element like this:
name = oForm.elements["name"].value;

6.7.2 Value for Text Area Element

Figure 6.4: Text Area Element

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