41.How to print a web page using javascript?

JavaScript helps you to implement this functionality using print function of window object. The JavaScript print function window.print() will print the current web page when executed.

42.What is Date object in JavaScript?

The Date object is a datatype built into the JavaScript language. Date objects are created with the new Date( ).

Once a Date object is created, a number of methods allow you to operate on it. Most methods simply allow you to get and set the year, month, day, hour, minute, second, and millisecond fields of the object, using either local time or UTC (universal, or GMT) time.

43.What is Number object in JavaScript?

The Number object represents numerical date, either integers or floating-point numbers. In general, you do not need to worry about Number objects because the browser automatically converts number literals to instances of the number class.
Syntax −
Creating a number object −

44.How to handle exceptions in JavaScript?

The latest versions of JavaScript added exception handling capabilities. JavaScript implements the try...catch...finally construct as well as the throw operator to handle exceptions.

You can catch programmer-generated and runtime exceptions, but you cannot catch JavaScript syntax errors.

45.What is purpose of onError event handler in JavaScript?

The onerror event handler was the first feature to facilitate error handling for JavaScript. The error event is fired on the window object whenever an exception occurs on the page.

The onerror event handler provides three pieces of information to identify the exact nature of the error −

Error message − The same message that the browser would display for the given error.

URL − The file in which the error occurred.

Line number − The line number in the given URL that caused the error.

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