W3C documentation reads the InputEvent should be cancellable: But in Chrome and Firefox you get cancellable set to false. The keypress event is fired when a key that produces a character value is pressed down. Relevance. Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, PHP, Python, Bootstrap, Java and XML. Once the user presses the Enter key, all characters typed are read and returned as a string: >>>. print 'Enter whole meters only! The return value of this method will be only of the string data type. Ideally a good program should use some form of validation checks to ensure that the user is providing their answers in the correct format. I defined depth test as a function so it can be reused. for example, I have three plans, they're B, D,W, I want the user to only pick one of these, otherwise they get a loop. https://www.w3.org/TR/DOM-Level-3-Events/#event-type-keypress, A Clean and Simple Approach for Unit Testing in TypeScript or JavaScript, JavaScript Best Practices — Functions and Parameters, Say goodbye to Prop Drilling with Contexts, Write Better JavaScript by Separating Side Effects From Logic, How to Toggle Caching for Routing Components in Angular, How to fetch APIs in react and effectively use data responses to create graphs using recharts, Testing Content Security Policy Headers With Nightwatch and Express. Python tutorial to call a function using keyword argument. @pyguy62: You use the return value from other function or main code for value of variable or return value is printed like in my edited post. We equally welcome both specific questions as well as open-ended discussions. How to limit the input of a raw_input. Syntax : string.ascii_letters. 1. raw_input() This method of Python reads the input line or string and also can read commands from users or data entered using the console. You can probably come up with many scenarios like this - e.g. After some testing (11/06/2018) when you call preventDefault() on the InputEvent it does not actually prevent putting the character into the (both Chrome and Firefox) even though it should. Though to avoid sending form with invalid characters in I also have the pattern attribute that is being consulted at