Basic JavaScript Interview Questions and Answers

6 :: What are JavaScript Data Types?

JavaScript Data Types are Number, String, Boolean, Function, Object, Null, Undefined

Is This Answer Correct?    26 Yes 1 No

7 :: How do you convert numbers between different bases in JavaScript?

Use the parseInt() function, that takes a string as the first parameter, and the base as a second parameter. So to convert hexadecimal 3F to decimal, use parseInt (" 3F" , 16)

Is This Answer Correct?    9 Yes 5 No

8 :: How to create arrays in JavaScript?

We can declare an array like this
var scripts = new Array()
We can add elements to this array like this

scripts[0] = " PHP"
scripts[1] = " ASP"
scripts[2] = " JavaScript"
scripts[3] = " HTML"

Now our array scripts have 4 elements inside it and we can print or access them by using their index number. Note that index number starts from 0. To get the third element of the array we have to use the index number 2. Here is the way to get the third element of an array.
document.write(scripts[2])
We also can create an array like this
var no_array = new Array(21, 22, 23, 24, 25)

Is This Answer Correct?    14 Yes 0 No

9 :: How do you target a specific frame from a hyperlink in JavaScript?

Include the name of the frame in the target attribute of the hyperlink in JavaScript. < a href=”http://www.globalguideline.com” target=”myframe”> Global Guide Line< /a>

Is This Answer Correct?    8 Yes 0 No

10 :: What are a fixed-width table and its advantages in JavaScript?

Fixed width tables are rendered by the browser based on the widths of the columns in the first row, in JavaScript resulting in a faster display in case of large tables. Use the CSS style table-layout:fixed to specify a fixed width table.
If the table is not specified to be of fixed width in JavaScript, the browser has to wait till all data is downloaded and then infer the best width for each of the columns. This process can be very slow for large tables.

Is This Answer Correct?    4 Yes 1 No