| Method | Usage | Description |
|---|---|---|
| prompt() | var name=prompt("What is your name?");
var person = prompt("Please enter your name","Harry Potter"); prompt(text,defaultText) //defaultText is optional |
Display a prompt box, asking the user to enter something.
The prompt() method returns the input value if the user clicks "OK". If the user clicks "cancel" the method returns null. |
| alert() | alert("You have 5 minutes left!"); | Display an alert box |
| confirm() | confirm("Are you sure you want to exit?"); | Displays a dialog box with a specified message, along with an OK and a Cancel button. |
| parseInt() | var num=prompt("Enter a number");
entry=parseInt(entryA); |
Converts the string that's passed to it to an integer. If it can't convert it, it returns NaN. |
| parseFloat() | var grade=prompt("Enter a grade", "99.50");
grade=parseFloat(grade); |
Converts the string that's passed to it to an decimal data type. If it can't convert it, it returns NaN. |
| setTimeout() | setTimeout(function(){ alert("Hello"); }, 3000); | Calls a function after a specified number of milliseconds. |
| clearTimeout() | clearTimeout(myVar); | clears a timer set with the setTimeout() method. |
| setInterval() | setInterval(function(){ alert("Hello"); }, 3000); | Calls a function at specified intervals (in milliseconds). Will continue calling the function until clearInterval() is called, or the window is closed. |
| clearInterval() | clearInterval(myVar); | clears a timer set with the setInterval() method. |
| Property or Method | Usage | Description |
|---|---|---|
| document.write() | document.write("Hello World!<br>"); | Writes to the document. |
| getElementById() | document.getElementById(id) | get the element with a specified id |
| getElementsByTagName() | document.getElementsByTagName("p") | gets the elements with the specified tagname |
| innerHTML | document.getElementByID('id').innerHTML | the inner HTML of that element |
| focus() | document.getElementById("myAnchor").focus(); | Give focus to an element |
| getAttribute() | var x = document.getElementsByTagName("H1")[0].getAttribute("class"); | Returns the value of the attribute with the specified name of an element. |
| Property | Usage | Description |
|---|---|---|
| onclick() | <button type="button" onclick="buttonFunction()">Click Me</button> | The event occurs when the user clicks on an element. |
| onload() | <body onload="loadFunction()">
window.onload=function(){ ... } |
The event occurs when a document has been loaded. |
| onmouseover() | <p onmouseover="mouseOverFunction()">Text Text Text</p> | The event occurs when the pointer is moved onto an element. |
| onmouseout() | <p onmouseout="mouseOutFunction()">Text Text Text</p> | The event occurs when a user moves the mouse pointer out of an element |
| Function | Usage | Description |
|---|---|---|
| isNaN() | isNaN(x) | Checks if x is an illegal number. |
| Property | Usage | Description |
|---|---|---|
| prototype | employee.prototype.salary=null; | The prototype property allows you to add properties and methods to an object. |
| Operator | Usage | Description |
|---|---|---|
| instanceof | if(s1 instanceof Object) | used to check the type of an object at run time. |
More events go here: http://www.w3schools.com/jsref/dom_obj_event.asp
For more on JavaScript Go to: http://www.w3schools.com/jsref/default.asp