I've also used this in cases where I have a menu and some of the items are different depending on the user. so the empty array disappears, or our value gets added to the new array. The conditional (ternary) operator is the only JavaScript operator that takes three operands: a condition followed by a question mark ( ), then an expression to execute if the condition is truthy followed by a colon (: ), and finally the expression to execute if the condition is falsy. The / / in line 2 identifies to JavaScript that the characters in between are part of the regular expression. (condition arr1 : ) console. You could just do the below: const string The cat sat on the mat const regex /sat/ regex.test(string) // result: true This basically tests the string to see if the word sat exists in the string. The array spread syntax throws an error if you give it a false (which works ok for objects) so instead of an & operator, I use a ternary ? operator instead and either return the value in an array, or a blank array. You could use the conditional operator instead, and spread an empty array if the condition is false: let condition false let arr1 'value1' let arr2 'value2'. Now you can call your function getUser(username, true) for the full details, and getUser(username, false) if you don't need the extra info! Same pattern for conditionally adding items to arraysĪs I mentioned at the start of this post - you can use a very similar pattern for arrays. Here's the pattern I use: const myObject = The keyword if tells JavaScript to execute the code in the curly braces under certain conditions. Instead of removing properties, we're adding them - but only sometimes! If statements are used to make decisions in code. In this post, we will look at a pattern that does the opposite. What Javascript code matches this statement: Their name is Kim and they are less than 16 years old. Description of the problem: I cant load my experiment to. In my last blog post, I wrote about an interesting pattern for copying an object without a specific property. JavaScript conditional statement Online experiments code kaylap April 18, 2022, 12:31pm 1. Perfect when you (sometimes) want to add a key to an object. It uses the spread syntax (.) to conditionally add a property to an object, or an item to an array. Here's the conditional object property pattern.
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