function checkArray() { let emptyArray = []; let nonExistantArray = undefined; let fineArray = [1, 2, 3, 4, 5]; if(Array.isArray(emptyArray) && emptyArray.length) output = true; else output = false; document.querySelector('.output-empty').textContent = output; if(Array.isArray(...
2, 3, 4, 5]单击按钮,检查数组是否存在且不为空检查数组数组emptyArray是否为空或存在:数组nonExistantArray是否为空或存在:数组fineArray是否为空或存在:functioncheckArray
如上的方法我们都不能来判断一个对象是否为数组的方式; 但是我们在看ECMA262中可以看到,可以使用 Object.prototype.toString.call()方法来判断一个对象是否为数组;如下代码: functionisArray(obj){returnObject.prototype.toString.call(obj)=='[object Array]';}//代码调用console.log(isArray([]));//trueconsol...
Check if an object is an array: constfruits = ["Banana","Orange","Apple","Mango"]; letresult = Array.isArray(fruits); Try it Yourself » Check if another datatype is an array: lettext ="W3Schools"; letresult = Array.isArray(text); ...
includes()Check if an array contains the specified element indexOf()Search the array for an element and returns its position isArray()Checks whether an object is an array join()Joins all elements of an array into a string keys()Returns a Array Iteration Object, containing the keys of the ...
functionisArray(o) { returnObject.prototype.toString.call(o)==='[object Array]'; } 因为是字符串比较,也就解决了环境问题和语法灵活性所带来的变化,因此比较稳定。好,讲到现在,想必大家对javascript类型判断应该有一个较为深入的理解,我想通过自已的能力,应该也可以写一个比较完善的类型判断函数,那下面就来...
判断时使用Object.prototype.toString.call( list )==='[object Array]'或者Object.prototype.toString.call( list )=='[object Array]',==或者===一样的效果。 测试3: 如果使用jquery,可以使用$.isArray(obj)的方法,如下: vara = ["A", "AA", "AAA"];if($.isArray(a)) { ...
constarray=['🍝','🍜','🍲'];constnotArray='not array';_.isArray(array);// true_.isArray(notArray);// false Yes, the syntax is the same as Lodash 🤓 #Why can't we usetypeof? Often, we want to check the type of a value, we simply usetypeof ...
if (typeof data === 'object' && !Array.isArray(data)) { dataobj.push(data); } else { dataobj = data; } if (Array.isArray(dataobj)) { for (var i1 = 0; i1 < dataobj.length; i1++) { var keys = Object.keys(dataobj[i1]), check = ''; ...
This guy is the slowest for trying to check for an Array. However, this is a one stop shop for any type you're looking for. However, since you're looking for an array, just use the fastest method above. Also, I ran some test: So have some fun and check it out....