1. searching Concept: Linear search Binary search
We have a list or array of items
We want to determine if a particular key is in the list
Linear search
Search items, one by one
On average each search considers half of the list
Binary search
The list must be in sorted
Each search requires log2 list size compares

2. Linear search code
private boolean linearSearch (Comparable[] data, Comparable which) { for (int i=0; i<data.length; i++) if (data[i].compareTo(which)==0) return true; } return false;

3. Binary Search code
private boolean binarySearch(Comparable[] data, Comparable which) { int low=-1, high = data.length, middle, compare; while (low+1<high) middle = (low + high)/2; compare = data[middle].compareTo(which); if (compare==0) return true; else if (compare<0) low = middle; else high =middle; } return false;

4. Generic search code Linear Search
private boolean genericSearch(ArrayList dataList, Comparable which) {
return (dataList.contains(which)) ? true: false; }
Binary Search
return (Collections.binarySearch(dataList, which)>=0)? true: false;