If you don't do this, the logical && operation will return the last value or the first falsy value. For example: const isEmpty = (arr) => !Array.isArray(arr) || !arr.length; const hasElems = (arr) => Array.isArray(arr) && !!arr.length; const arr = []; console.log(is...
Example 2 : React check if string is null or empty In this second example of this tutorial, we use React JS to check if a string is empty or null using a simple condition. The condition is !str || str.trim() === "", which means that the string is either falsy (such as null,...
{}, ['foo']); => false is.any.empty([], 42); => true // 'all' and 'any' interfaces can also take array parameter is.all.empty([{}, 'foo']); => false is
Javascript - Assign 0 if the value is null or empty in, Using || operator or just a simple ternary operator would work if its null, undefined or ''. But it won't work for a blank space like this one ' ' (since Boolean (' ') evaluates as true) which it's not good if you wa...
If we were creating an array, it would be an empty array. Next, we need to figure out what the parameters are for the function we pass to .reduce. In our example, we named them total and num. Remember, this function is going to be called for each element in the array. The reason...
All empty values, if the property accepts them, are normalised to undefined. Properties are only linked to attributes if the attribute option is set. Each built-in property, if possible, will supply a deserialize and serialize option but will not be linked by default. array The array property...
Node.js, Frontend, SSR: npm install is-it-check Bower: bower install is-it-check Build: npm run build Test: npm test Use like any other library in your js or ts code... importisfrom'is-it-check'// some examplesis.ipv4('198.12.3.142')// trueis.array(['foo','bar','baz'])/...
We can also check if a variable stores a truthy value. Truthful values are all values that are not false. Falsy values in JavaScript are:undefined,null,false, ,0,""(empty string),NaN(not a number). import{useEffect, useState}from'react'; ...
is.empty(value:array|object|string) Checks if the given value is empty. is.existy(value:any) Checks if the given value is existy. (not null or undefined) is.truthy(value:any) Checks if the given value is truthy. (existy and not false) is.falsy(value:any) Checks if the given valu...
is.js是一个强大的通用js校验工具类。你可以使用js.js来检测任何东西,例如检测所给的值是否为参数,是否是数组,是否是超链接,...,甚至可以检测浏览器类型,正则表达式和数学表达式等等。 is.js根据检测的类型分为:类型检测、正则表达式检测、算数检测、环境检测、时间检测、Presence检测、对象检测、字符串检测数组检测...