Check if something is aNode.js stream Install npm install is-stream Usage importfsfrom'node:fs';import{isStream}from'is-stream';isStream(fs.createReadStream('unicorn.png'));//=> trueisStream({});//=> false API isStream(stream, options?) ...
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?
str3 = new String('Great Place'); Now to check whether a given variable is a string or not, we'll use a JavaScript operator calledtypeof. Syntax: typeof variable; This operator returns the data type of the variable specified after it. If the variable is of string data type, it will...
Checks if value is classified as an Array object. constarray=['🍝','🍜','🍲'];constnotArray='not array';_.isArray(array);// true_.isArray(notArray);// false Underscore Returns true if object is an Array. constarray=['🍝','🍜','🍲'];constnotArray='not array';_.isArr...
if (typeof someVar === 'undefined') { console.log('Undefined variable'); } else if (typeof someVar === 'null') { console.log('Null-value'); } This code also results in: Undefined variable Technically speaking, some_var is an undefined variable, as it has no assignment. On th...
It's absolutely not necessary to have a dependency if we don't need Lodash for something else, but, if we already have that dependency, we can make use of the _.isString() method, which returns true if the specified value is a string primitive or a String object, making it fit for...
As of ES-Check version2.0.2, a better debugging interface is provided. When a file errors, An error object will be logged with: the erroring file the error the error stack ⚠️NOTE:Error logs are from the Acorn parser while parsing JavaScript related to specific versions of ECMAScript....
. Check is object null - What are the options? .Net 4 FileLoadException permissions problem With windows service .NET code to extract data from an excel sheet and create a text file having a specific format .Net Core 3.0 Console App. Microsoft.Data.SQLClient is not supported .NET Core su...
C# Regex Remove JavaScript from returned HTML help needed c# return name of object C# string is not null C# Syntax on escape character for "/" c# xml the process cannot access the file because it is being used by another process C#: Visible = true not working C#.net Export to excel...
onclick in JavaScript focuses on only one event to call the callback function. This method also emphasizes executing a function body that is declared after the initiation of the method. But first, the onclick method requires an object to be followed. The HTML element’s querySelector defines...