JAVA的一维数组的声明方式:
type var[]; 或type[] var;
声明数组时不能指定其长度(数组中元素的个数),
Java中使用关键字new创建数组对象,格式为:
数组名 = new 数组元素的类型 [数组元素的个数]
// orderedArray.java // demonstrates ordered array class // to run this program: C>java OrderedApp //////////////////////////////////////////////////////////////// class OrdArray { private long[] a; // ref to array a private int nElems; // number of data items //----------------------------------------------------------- public OrdArray(int max) // constructor { a = new long[max]; // create array nElems = 0; } //----------------------------------------------------------- public int size() { return nElems; } //----------------------------------------------------------- public int find(long searchKey) { int lowerBound = 0; int upperBound = nElems-1; int curIn; while(true) { curIn = (lowerBound + upperBound ) / 2; if(a[curIn]==searchKey) return curIn; // found it else if(lowerBound > upperBound) return nElems; // can't find it else // divide range { if(a[curIn] < searchKey) lowerBound = curIn + 1; // it's in upper half else upperBound = curIn - 1; // it's in lower half } // end else divide range } // end while } // end find() //----------------------------------------------------------- public void insert(long value) // put element into array { int j; for(j=0; j<nElems; j++) // find where it goes if(a[j] > value) // (linear search) break; for(int k=nElems; k>j; k--) // move bigger ones up a[k] = a[k-1]; a[j] = value; // insert it nElems++; // increment size } // end insert() //----------------------------------------------------------- public boolean delete(long value) { int j = find(value); if(j==nElems) // can't find it return false; else // found it { for(int k=j; k<nElems; k++) // move bigger ones down a[k] = a[k+1]; nElems--; // decrement size return true; } } // end delete() //----------------------------------------------------------- public void display() // displays array contents { for(int j=0; j<nElems; j++) // for each element, System.out.print(a[j] + " "); // display it System.out.println(""); } //----------------------------------------------------------- } // end class OrdArray //////////////////////////////////////////////////////////////// class OrderedApp { public static void main(String[] args) { int maxSize = 100; // array size OrdArray arr; // reference to array arr = new OrdArray(maxSize); // create the array arr.insert(77); // insert 10 items arr.insert(99); arr.insert(44); arr.insert(55); arr.insert(22); arr.insert(88); arr.insert(11); arr.insert(00); arr.insert(66); arr.insert(33); int searchKey = 55; // search for item if( arr.find(searchKey) != arr.size() ) System.out.println("Found " + searchKey); else System.out.println("Can't find " + searchKey); arr.display(); // display items arr.delete(00); // delete 3 items arr.delete(55); arr.delete(99); arr.display(); // display items again } // end main() } // end class OrderedApp