constisEmpty=require('check-empty-string');// When displayed on screen, it's a blank usernameconstrawUsername='\u202E\u202E\u202E\n'// they are not conventional spaces// JavaScriptif(rawUsername.trim().length<2){console.error('Invalid username!');};// check-empty-stringif(isEmpty....
Learn how to check if an input field is empty in React using different methods, such as empty string validation, react hook form, and JavaScript. This tutorial will show you how to handle empty field validation in React JS with examples
How to Check String is Empty or Not in Javascript? In this example, we use JavaScript to check string is empty or null using !str || str.trim().length === 0;. This expression evaluates to true if the string is empty or null, and false otherwise. You can check and edit this code...
const isEmpty2 = check(emptyString, 'nonEmpty'); console.log(isEmpty2); // 输出: false 在这个例子中,check函数接受两个参数:input是要检查的值,type是检查的类型(在这个例子中是'nonEmpty',表示非空检查)。函数内部使用switch语句根据type参数执行不同的检查逻辑。如果input字符串不是空的(不是null、unde...
const empty = {}; Object.keys(empty).length === 0 && empty.constructor === Object; # Why do we need an additional constructor check?You may be wondering why do we need the constructor check. Well, it's to cover for the wrapper instances. In JavaScript, we have 9 built-in ...
check.emptyString(''); // true check.emptyString(' '); // false check.emptyString(0); // false check.emptyString([]); // false check.emptycheck.empty([]); // true check.empty(''); // true check.empty({}); // true check.empty(0); // false check.empty(['foo']); //...
check.object(thing): Returnstrueifthingis a plain-old JavaScript object,falseotherwise. check.emptyObject(thing): Returnstrueifthingis an empty object,falseotherwise. check.nonEmptyObject(thing): Returnstrueifthingis a non-empty object,falseotherwise. ...
JavaScript Code: // Define a function named 'test' that checks if a given string is a palindromeconsttest=(text)=>{// Check if the input is not a stringif(typeoftext!=='string'){return'String should not be empty!';}// Check if the length of the string is less than or equal to...
See the Pen JavaScript Check whether a string is blank or not - string-ex-2 by w3resource (@w3resource) on CodePen.For more Practice: Solve these Related Problems:Write a JavaScript function that checks if a string is empty or contains only whitespace using trim(). Write a JavaScript ...
MY_STRING="" if [ -z $MYSTRING ] then echo "String is empty" else echo "String is not empty" fi For more Shell scripting tips,check out or Bash/Shell scripting articles!