數(shù)組
查找下標(biāo)：
class Demo1 {
public static void main(String[] args) {
int [] arr = {1, 3, 23, 34, 5, 56, 7, 8, 9, 10};
int ret = findIndex(arr, 34);
if (ret != -1) {
System.out.println("ret = " + ret );
}else {
System.out.println("not,found.!" );
}
}
public static int findIndex(int[] array,int number) {
if (null == array || array.length == 0) {
System.out.println("傳入?yún)?shù)不合法");
return -1;
}
int index = -1;
for (int i = 0; i < array.length; i++) {
if (number == array[i]) {
index = i;
}
}
return index; ?
}
}
查最大值：
public class Demo2 {
public static void main(String[] args) {
int[] arr = new int[10];
getNumberFromStdin(arr);
int ret = findMaxIndex(arr);
if (ret != -1) {
System.out.println("Max is " + arr[ret] + " at " + ret);
}
}
public static int findMaxIndex(int[] array) {
//1. 參數(shù)合法性判斷
if (null == array || array.length == 0) {
System.out.println("傳入?yún)?shù)不合法！");
return -1;
}
//2. 假設(shè)下標(biāo)為0的元素是數(shù)組中的最大值
int index = 0;
for (int i = 1; i < array.length; i++) {
//如果當(dāng)前index下標(biāo)的數(shù)據(jù)小于下標(biāo)為i的元素，證明當(dāng)前
//Index保存的不是最大值，把i的值賦值給index 保存
if (array[index] < array[i]) {
index = i;
}
}
return index;
}
public static void getNumberFromStdin(int[] array) {
//1. 參數(shù)合法性判斷
if (null == array) {
System.out.println("傳入?yún)?shù)不合法");
return;
}
Scanner sc = new Scanner(System.in);
//2. 利用for循環(huán)從鍵盤上獲取用戶輸入的int類型數(shù)據(jù)
for (int i = 0; i < array.length; i++) {
array[i] = sc.nextInt();
}
}
}
