Arrays

1. Arrays A list of values Conceptually, a continuous memory space

2. public String() {  this.offset = 0;   this.count = 0;   this.value = new char[0];   }

3. i e C o c n e c u e p m r S t String Name = new String (“Computer Science”); name “Computer Science” name 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 “Computer Science”.subString(4,8) returns “uter “ name.subString(4,8) returns “uter”

4. 1000 numbers • smallest

5. int[] height = new int[11] • int[] does not includes the size • Instantiation height using new Bound checking – automatic height[index] If index = 10 If index = 12 ArrayIndexOUtOfBoundsException

6. int[] height; • int height[]; • int[] scores = {87,98,68,87,65,100} • Char[] vowels = {‘A’, ‘E’, ‘I’, ’O’, ’U’}

7. Array as parameters • Array is an object (call by reference) • copy the reference • call by value if array element

8. Arrays of objects • String[] words = new String[5]; words

9. For (int index = 0; index < LIMIT; index++) • system.out.println(list[index]); For (int value : list) System.out.println(value);

10. Grade Grade Range

11. int[] anArray ; • byte[] anArrayOfBytes; • short[] anArrayOfShorts; • long[] anArrayOfLongs; • float[] • char[] anArrayOfChars; • String[] anArrayOfStrings;

12. Using final tag. for(index = 0; index < final; index ++) section= scan.nextInt(); Read data until the read data is meaningless For example if the section number is 0, stop section = scan.nextInt(); While (section != 0) { statement(s); section = scan,nextInt(); }

13. Read up to 50 students5 scores / studentGrade depends on Avg.highest grade and namelowest grade and name • Student Section Private avg Private gNoA Instantiate 6 students object letterGrade lowerBound numbers names chagenumber getnumber Getname changename

14. Multi dimension • Array whose components are themselves array • Array element is an array MArray

15. Multi dimensional array –java does not directly support • Use array of array reference • Ragged array

16. arraycopy • char[] copyFrom = { 'd', 'e', 'c', 'a', 'f', 'f', 'e', 'i', 'n', 'a', 't', 'e', 'd' }; • char[] copyTo = new char[7]; • for (i=2; i<=7; i++) • copyTo[i] = copyFrom[i];