In this tutorial, you will find some built-in methods how to check if an array or object is empty in React JS applications. How to Check if Array or Object is Empty in React Js Here are some built-in methods that allow users to check whether an array or object is empty or not: Me...
To check if a JavaScript array is empty or not, you can make either of the following checks (depending on your use case): const empty = !Array.isArray(array) || !array.length; const notEmpty = Array.isArray(array
Vue.JS check if Array,Object or String is empty: In Vue.js, To check if an array is empty in Vue.js, you can use the Array.length property, which returns the number of elements in the array To check if the string is empty in Vue.js, you can use the
log(isEmptyObject(bar)); // output: false As you can see, the Object.entries() method converts an object into an array, and we can count the length of that array to check if the object in question is empty. This is very similar to the Object.keys() method and will give the ...
isObjectEmpty(new String()); // false ✅ isObjectEmpty(new Number()); // false ✅ isObjectEmpty(new Boolean()); // false ✅ isObjectEmpty(new Array()); // false ✅ isObjectEmpty(new RegExp()); // false ✅ isObjectEmpty(new Function()); // false ✅ isObjectEmpty(...
If the array contains more than 0 keys, the object isn't empty.You could also do the check implicitly, e.g.: index.js if ([].length) { // 👉️ if this runs, the array is not empty } In this example, we access the length property on an empty array, which evaluates to 0...
js判断空数组 方法一 Array.isArray && arr.length 通过Array.isArray来判断是否为数组,再通过length属性。...只是判断数组的方法不一样而已。 使用typeof来检测是否为数组,再通过length属性。...arr && typeof arr === "object" && arr.constructor === Array && arr.length 注:typeof判断数组和null的时候...
post.capabilities.items仍然会被定义，因为它是一个空数组，如果你检查post.capabilities.items.length，它...
The Object.keys() method is the best way to check if an object is empty because it is supported by almost all browsers, including IE9+. It returns an array of a given object's own property names. So we can simply check the length of the array afterward: Object.keys({}).length ==...
The indexOf() method returns -1 if the value is not contained in the array. If the returned index is -1, push the value into the array. index.js const arr1 = ['a', 'b', 'c', 'd']; const value1 = 'e'; if (arr1.indexOf(value1) === -1) { arr1.push(value1); }...