When variables have the same purpose in a program, it is often more efficient to use an array.
The program below reads in three numbers, then prints them.
The statement double[] num= new double[3]; allocates space in memory for three decimal numbers. The three numbers are referred to as num[0], num[1], and num[2]. In speaking we often say "num sub 1." where "sub" is short for "subscript".
The number inside brackets is the subscript or index. The subscripts always start with 0.
Once a variable is declared as an array, the subscript must be included to refer to the elements.
One of the advantages of an array is that the subscript can be a variable. A for loop can be used to read in an array of numbers or print them out.
Input 3 numbers