FAQ for Java_ Arrays

1 classArrayDemo22 {3      Public Static voidMain (string[] args)4     {5         /*int[] arr= new int[3];6 System.out.println (arr[3]);7 //Arrayindexoutofboundsexception:3 8//When you access a corner label that does not exist in the array, it will occur at run time when the corner is out of bounds exception. */9arr =NULL;//arr does not point to an array entityTenSystem.out.println (arr[0]); One         //nullpointerexception: null pointer exception 12//When a reference variable does not have any entities pointing, an exception occurs when a specific entity is manipulated with a change in volume -  -  the         //Both of these issues occur at run time, and compilation does not error -  -  -     } + } -  +  A classArrAyDemo3 at { -      Public Static voidMain (string[] args) -     { -         /* - int[] arr = new int[3]; -  in The second way of defining: - When the array is defined, the length of the array is defined, and the type also defines the contents of the element.  to element type [] Array name = new element type []{element, Element, ....}; +  -         */ the  *         int[] arr=New int[]{46,98,24};//brackets in the back do not write element lengths $         /*Panax Notoginseng there are several elements in the array, in fact the array is the clearest - The length of the array (number of elements) can be obtained directly from an attribute of the array entity with length the  +         */ ASystem.out.println ("length=" +arr.length); the          for(intx=0;x<arr.length; x + + ) +         { - System.out.println (arr[x]); $         } $         /* - The core idea of manipulating an array is that it is a corner mark that can be accessed by an array of elements in a corner: (Set and get) -  the usually the most basic action of array manipulation is: traversal. Manipulating arrays by looping -         */Wuyi     } the}

FAQ for Java_ Arrays