Technology Questions

Oracle constraints are used to maintain consistent of data and ensure the data is properly maintained. A constraint is more or less a restriction we try to apply on a table.
Types of constraints:
- Check constraints
- NOT NULL constraint
- PRIMARY KEY constraint
- REFERENCES constraint
- UNIQUE constraint

Canvas is an element that is used for the graphics for the web page. It uses JavaScript to bring the graphics functionality live. It allows easy way to draw the graphics and use different types of tools to create drawing on the web page. Canvas is just a rectangular area that controls the pixel of every element that is used in the web page. Canvas uses methods like paths, circles, etc. The canvas element will be used as follows:

<canvas id="can" width="200" height="100"></canvas>

The canvas element includes id, width and height settings and with the javascript it gets used like:

<script type="text/javascript">

var c=document.getElementById("can");

var ctx=c.getContext("2d");

ctx.fillStyle="#FF0000";

ctx.fillRect(0,0,150,75);

</script>

In general, a Nine-patch image allows resizing that can be used as background or other image size requirements for the target device. The Nine-patch refers to the way you can resize the image: 4 corners that are unscaled, 4 edges that are scaled in 1 axis, and the middle one that can be scaled into both axes.

Outside the package if any other class other than JVM calls the finalize method our class then it is not allowed

The .Net runtime knows about all the references between the objects. It can identify all the circular references that are reachable from the root and hence finalize them to free them all at once if and when needed.

ADO or Active X Data objects, allows developers to create applications that can interoperate well with other data application services.

Method contains name, parameters, return type and executable body. But block does not contains name, parameters, return type.It contains only executable body.

Methods are executed by method call statements. Blocks are executed automatically with class loading and with object creation.