You can test if a function exists in Javascript by simply testing for the name of it in an if() conditional. One thing to be aware of is that you can’t test for the function name by itself (well you can, but if it doesn’t exist the Javascript will error out); it’s a method...
Here, we will see how to check if a given key exists as a key-value pair inside a JavaScript Object? We will first see how it is done and then see a practical use case where you need to check if a certain key exists in a JavaScript Object?
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exists(path, function (doesExist) { if (doesExist) { console.log('file exists'); } else { console.log('file not found!'); } }); JavaScript Copy The parameter value will be true when the file exists otherwise it'll be false. Using accessSync method The accessSync method is used ...
Conclusion Now you know all about the four methods to check if a file exists using NodeJS. It’s recommended to usefs.existsSync()if you only need to check for the existence of a file. When you need to check for specific permissions as well, you can use eitherfs.accessSync()orfs.acce...
Check if a process is running check if a process or service is hanging/not responding? Check if a text file is blank in powershell check if computer exist in ou Check if drive exists, If not map Check if Email address exists in Office 365 and if exists, Create a Unique Email address...
function greet(name = "Guest") { console.log(`Hello, ${name}!`); } greet(); // Output: Hello, Guest! 3. Check for Undefined Values Before Accessing Properties When working with objects, it’s important to check if a property exists before accessing it. This avoids runtime errors or...
In PHP, we have function called file_exists, is there a similar function with sails.js? node.js sails.js Yes. Since Sails is created with Node.js you can usefs.exists. This will remove the file from the array if it's not found. You can load it into your view how you were before...
Check if the value exists in Array in Javascript Example: const fruits = ["Banana", "Orange", "Apple", "Mango"]; fruits.includes("Mango"); check if an item exists in an array: const nums = [ 1, 3, 5, 7]; console.log(nums.includes(3));...
//code to check if a value exists in an array using javascript for loop var fruits_arr = ['Apple', 'Mango', 'Grapes', 'Orange', 'Fig', 'Cherry']; function checkValue(value, arr) { var status = 'Not exist'; for (var i = 0; i < arr.length; i++) { var name = arr[...