Learn about problems encountered in Java (2)

When declaring an array in 1.java, you do not need to specify the number of elements in the array, the array names declared above cannot be used directly, and must be initialized and allocated for memory before they can be used.

such as int a[] = new INT[8];

2.DataInputStream provides many methods for reading data such as Boolean, Byte, character, Integer, Long integer, short integer, single precision, double precision, and dataoutstream for writing related types.

3. Use DataInputStream infile = new DataInputStream (new Bufferedinputstream (New FileInputStream (filepath)));

You must know the type of data stored in the file, or you will get an error!

4. Any object in Java should be NEW!!!

The 5.Integer object is replaced by the int type: Integer.intvalue ().

Learn about problems encountered in Java (2)