public class ArrayDefaultValue {                                       
    public static void main(String args[])
    {
        byte[]byteArray=new byte[1];
        char[]charArray=new char[1];
        int[]intArray=new int[1];
        long []longArray= new long[1];
        float []floatArray=new float[1];
        double []doubleArray=new double[1];
        String[]stringArray=new String[1];
        System.out.println("byte+"byteArray[0]);
        System.out.println("char+"charArray[0]);
        System.out.println("int+"intArray[0]);
        System.out.println("long+"longArray[0]);
        System.out.println("float+"floatArray[0]);
        System.out.println("double+"doubleArray[0]);
        System.out.println("string+"stringArray[0]);
    }   

}
运行结果。这是什么意思？
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
    The type of the expression must be an array type but it resolved to String
    Syntax error on token "byteArray", delete this token
    The type of the expression must be an array type but it resolved to String
    Syntax error on token "charArray", delete this token
    The type of the expression must be an array type but it resolved to String
    Syntax error on token "intArray", delete this token
    The type of the expression must be an array type but it resolved to String
    Syntax error on token "longArray", delete this token
    The type of the expression must be an array type but it resolved to String
    Syntax error on token "floatArray", delete this token
    The type of the expression must be an array type but it resolved to String
    Syntax error on token "doubleArray", delete this token
    The type of the expression must be an array type but it resolved to String
    Syntax error on token "stringArray", delete this token

    at ArrayDefaultValue.main(ArrayDefaultValue.java:12)

你用了关键字。。。。。

并不是 ，你是把+写在引号里面了，如果你要拼接字符串，你需要写成  System.out.println("ss"+byteArray[0]);
注意我的加号在引号外面！！！