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Get the Part Before First Occurrence in a String in JavaScript or Node.js Get the Part After First Occurrence in a String in JavaScript or Node.js Split a String into a List of Words in JavaScript or Node.jsĭetect if a String is in camelCase Format in Javascript or Node.jsĬheck If a String Is in Lowercase in JavaScript or Node.jsĬheck If a String is in Uppercase in JavaScript or Node.js Split a String into a List of Lines in JavaScript or Node.js Reverse a String in JavaScript or Node.js Split a String into a List of Characters in JavaScript and Node.js Limit and Truncate a String to a Given Length in JavaScript and Node.js How to Check if a Value is a String in JavaScript or Node.jsĬheck If a String Includes All Strings in JavaScript/Node.js/TypeScriptĬheck if a Value is a String in JavaScript and Node.js Get the Part After a Character in a String in JavaScript or Node.js Get the Part Before a Character in a String in JavaScript or Node.js Remove Numbers From a String in JavaScript or Node.js Remove Extra Spaces From a String in JavaScript or Node.js

Generate a Random ID or String in Node.js or JavaScript TypeScript has helped make my JavaScript code so much more robust than it had ever been before, and the continued development of the language has been making everything even better all the time.Remove All Whitespace From a String in JavaScript You have no choice but to deal with optionality and undefined in JavaScript, but the great news is that there are a lot of tools available with which to deal with them. type Foo = Dealing with optionality isn’t optional. First, if you don’t tell TypeScript that a property is optional, it will expect it to be set.

In strict mode, this means a couple of things. When you have a JavaScript object and you ask for a property that doesn’t exist, JavaScript will return undefined rather than throwing an error. I don’t think you can program JavaScript without having seen undefined is not a function at least once in your life - and once seems far too small a number. You must tell TypeScript if a property is optional.

TypeScript has tools to deal with all of these. A return value to indicate something that was requested is missing.A potentially-omitted optional argument to a function.An uninitialized or absent property of an object.Undefined typically shows up in a handful of key places: I recommend letting TypeScript be as strict as you can. What’s undefined?Ī project set up with TypeScript’s strict flag will check for all kinds of potential issues in your code. Thankfully, TypeScript is a great tool for helping you deal with it and writing better code in the process. Thinking about it all the time tends to break brains, though - and not thinking about it introduces bugs. It’s a standard way to say, “This thing you asked for doesn’t exist.” Working with JavaScript means working with undefined.