JavaScript comments can be used to explain JavaScript code, and to make it more readable. JavaScript comments can also be used to prevent execution, when testing alternative code. Single Line Comments Single line comments start with //. Any text between // and the end of the line will be ignored by JavaScript (will not be […]
JavaScript syntax is the set of rules, how JavaScript programs are constructed: var x, y; // How to declare variables x = 5; y = 6; // How to assign values z = x + y; // How to compute values JavaScript Values The JavaScript syntax defines two types of values: Fixed values and variable values. Fixed values are called literals. Variable values […]
Example var x, y, z; // Statement 1 x = 5; // Statement 2 y = 6; // Statement 3 z = x + y; // Statement 4 Try it Yourself » JavaScript Programs A computer program is a list of “instructions” to be “executed” by a computer. In a programming language, these programming instructions are called statements. A JavaScript program is a list of programming statements. In […]
JavaScript Display Possibilities JavaScript can “display” data in different ways: Writing into an HTML element, using innerHTML. Writing into the HTML output using document.write(). Writing into an alert box, using window.alert(). Writing into the browser console, using console.log(). Using innerHTML To access an HTML element, JavaScript can use the document.getElementById(id) method. The id attribute defines the HTML element. The innerHTML property defines the HTML content: […]
JavaScript makes HTML pages more dynamic and interactive. Example My First JavaScript Click me to display Date and Time Try it Yourself » The HTML <script> Tag The <script> tag is used to define a client-side script (JavaScript). The <script> element either contains scripting statements, or it points to an external script file through the src attribute. Common uses for JavaScript […]
