byte, int, String or double. Only variables of the appropriate type can be stored in an array. One array cannot store both ints and Strings, for instance.
Like all other variables in Java an array must be declared. When you declare an array variable you suffix the type with [] to indicate that this variable is an array. Here are some examples:
int[] k;
float[] yt;
String[] names;
k is an array of ints, yt is an array of floats and names is an array of Strings. In other words you declare an array like you declare any other variable except that you append brackets to the end of the type.You also have the option to append the brackets to the variable instead of the type.
int k[];
float yt[];
String names[];
int[] k[];
float[] yt[];
String[] names[];