CS 110 One Dimensional Arrays 1
Copyright C. Tanner 2009
• Array
o Collection of data
o Data strucutre
o Fixed number of items
o Each called an element
o All same data type
o Use them
Visit the data more than once
• Find those values > ave
• One dimensional array
o dataType [] name
o name = new dataType[size]
o elements 0-size-1
o to access an element use index (subscript)
non-negative integer < size
o [] array subscripting operator
• Specify size during execution
o int size;
o size = sc.nextInt();
o int [] a = new int[size];
• initialize an array
o double [] = { 1.2,3.4,5.6};
o size is determined by the number of elements
o String [] daysWeek = {“Sunday”, “Monday”, “Tuesday”, “Wednesday”,
“Thursday”, “friday”, “Saturday”};
o int [] primes={2,3,5,7,11,13,17,19,23,29};
o print the values in primes
System.out.print (“the prime numbers < 30”);
for (int i =0; i<primes.length;i++)
System.out.print (primes[i] + “’ “);
• length operator
o data field of an array
o not a method
o tells the number of elements in the array
o size
• Processing arrays
o For loop where the loop variable iterates through the elements of the
array
Initial 0
Increment 1
Variable < length
• Write a loop which will intitalize an array to -1
for (int i = 0; i < array.length; i++)
array[i] = -1;
