try statement allows to analyse block of code for errors. catch statement allows to handle error. throw statement allows to create custom errors. finally statement allows to carry out code, after try & catch, regardless of result. Try and Catch JS statements try and catch come in pairs. try { Block of code to try } catch(err) { Block of code to handle
Category: JS Tutorial
For Loop – JavaScript Basics
With help of Loop a block of code can carry work number of times. Instead of writing the same codes again and again use loop to make your work easy. Types Of Loops for = use to loop block of code number of times for/in = use to loop properties of an object while = use to loop block
Switch Statement – JavaScript Basics
It is used to perform different actions on different conditions. How does it works?? – switch expression is classified once & value of expression is compared with values of each case. The associated block of code is executed if there’s a match. <!DOCTYPE html> <html> <body> <p id=”ex”></p> <script> var day; switch (new Date().getDay()) { case
If…Else Statement – JavaScript Basics
When you write codes, most of the times you want to perform various actions for different decisions in your programs. We have the following conditional statements : if = defines block of code to be executed, if specified condition is true else = defines a block of code to be executed, if same condition is false else
Events – JavaScript Basics
Things that happen to HTML elements are HTML Events and JS can react on these events when JS is used in HTML pages. HTML event can be something that the user does. Some of the HTML events are :- an HTML button was clicked, HTML web page has finished loading. You might want to do
Variables – JavaScript Basics
Variables are the packages for storing the values. Lets take an example, suppose a,b,c are variables : <!DOCTYPE html> <html> <body> <h1>JS Variables</h1> <p> (a, b & c are variables!!) </p> <p id=”ex”></p> <script> var a = 10; var b = 20; var c = a + b; document.getElementById(“ex”).innerHTML = “Value Of C is =
Statements – JavaScript Basics
Statements are “instructions” to be “executed” by Web Browser. JS Statement This is a simple statement to write “Code Projects” inside Html element. <!DOCTYPE html> <html> <body> <h1>JS Statements</h1> <p>JS statements are executed by browser.</p> <p id=”ex”></p> <script> document.getElementById(“ex”).innerHTML = “Code Projects”; </script> </body> </html> Output : JS Programs JS programs
Syntax – JavaScript Basics
It is the set of the rules how programs are constructed. JS Programs : A computer program is list of “instructions” to be “executed” by computer. These program instructions are called statements in programming language. JS Statements are separated by semicolons; <!DOCTYPE html> <html> <body> <h1>JS Statements</h1> <p id=”ex”></p> <script> var x, y, z; x = 2; y =
Output – JavaScript Basics
Output can be displayed in different ways using JS. Using window.alert( ) This function is used to display a message alert. <!DOCTYPE html> <html> <body> <h1>Code Projects</h1> <p>Projects, Tutorials and More </p> <script> window.alert(“ALERT”); </script> </body> </html> Output : Using innerHTML document.getElementById(id) method can be used in JS to access HTML element. Html element is defined
Where To – JavaScript Basics
<script> Tag : JavaScript code must be located between opening and closing script tags ; <script> and </script> tags. <!DOCTYPE html> <html> <body> <h1>JavaScript Basics</h1> <p id=”ex”></p> <script> document.getElementById(“ex”).innerHTML = “Hello World! This Is My First JavaScript”; </script> </body> </html> Output : Block of JavaScript code that can be executed when “called” is