【leetcode】1250. Check If It Is a Good Array 题目如下: Given an arraynumsof positive integers. Your task is to select some subset ofnums, multiply each element by an integer and add all these numbers. The array is said to be good if you can obtain a sum of1from the array by any...
Array.isArray()方法的优点是兼容性好，可以在不支持instanceof运算符的旧浏览器中使用。但是，Array.is...
this===undefined;return'Undefined'this===null;return'Null'O=ToObject(thisvalue)把当前对象转换成Object 因为js中Object key值只允许string或者Symbol类型IsArray(O)判断是否是数组对象 IsArray判断逻辑:Type(O)判断是否是Object,不是直接returnfalse;O是否为Array exotic object: 如果O的[[DefineOwnProperty]]和...
if (typeof Array.isArray === "function") { return Array.isArray(value); }else{ return Object.prototype.toString.call(value) === "[object Array]"; } } alert(isArrayFn(arr));//结果 true alert(isArrayFn(arr2));// 结果 true 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11....
Array.isArray() 用来检验是不是数组 vara = [1,2,3] console.log(typeofa);//objectconsole.log(Array.isArray(a));//true 可以看出 typeof 并不能检验数组,虽然 Array.isArray() 可以检验数组,但是 IE8 都不兼容 vara = [1,2,3] alert(Object.prototype.toString.call(a))//[object Array] ...
file){ if (ObjectUtils.isEmpty(file) || file.getSize() <= 0) { throw new SystemException("上传文件大小为空 6.9K10 JavaScript中为空判断 JavaScript和Java不一样的地方是,Java中判断是否为空只要判断是否等于null就可以了,可是在JavaScript中却不能这样,因为还存在在这另外的几种情况。...下面看看具体...
arr&&typeofarr==="object"&&arr.constructor===Array&&arr.length 注:typeof判断数组和null的时候返回的是”object”。 代码语言:javascript 复制 vararr=newArray();//输出为it is trueif(arr){console.log("it is true");}//输出为it is falseif(arr==true){console.log("it is true")}else{conso...
[ObjCRuntime.Introduced(ObjCRuntime.PlatformName.iOS, 9, 0, ObjCRuntime.PlatformArchitecture.All, null)] [ObjCRuntime.Introduced(ObjCRuntime.PlatformName.MacOSX, 10, 11, ObjCRuntime.PlatformArchitecture.All, null)] public virtual bool IsArray { [Foundation.Export("isArray")] [ObjCRuntime...
pure_funcs (default: null)— You can pass an array of names and UglifyJS will assume that those functions do not produce side effects. DANGER: will not check if the name is redefined in scope. An example case here, for instance var q = Math.floor(a/b). If variable q is not used...
Check out #28029 to see how the official example was updated to restore the previous look. The async parse method of USDZLoader has been renamed to parseAsync(). The new parse() method can be used with classic callbacks. The shader chunk lightmap_fragment has been removed. If your ...