Objects don't have a .length property. A simple solution if you know you don't have to worry about hasOwnProperty checks, would be to do ... ... <看更多>

It is possible to have an array that has a set length, but all of the elements are undefined. This is the case if the array is created from an ... ... <看更多>

Javascript array.length returns undefinedArray length is undefined when stored in variableMyArray.length returns undefined... - JavaScript The Magic Behind ... ... <看更多>

This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.) This ... ... <看更多>

Both start and stop parameters are optional. The start parameter determines the zero-based index at which to start extraction. If the start is undefined , slice ... ... <看更多>

According to the documentation, Arrays must be defined as int myArray[10]; where 10 can be substituted for a known length (another integer), or filled with an ... ... <看更多>