16.数组使用

数组使用

1.打印全部元素

int[] arrays = {1,2,3,4,5};
for (int i = 0; i < arrays.length; i++) {
    System.out.println(arrays[i]);
}

//强化for循环，这个循环中的元素没有下标
for (int array : arrays) {
    System.out.println(array);
}

2.计算元素和

int[] arrays = {1,2,3,4,5};
int sum = 0;
for (int i = 0; i < arrays.length; i++) {
    sum += arrays[i];
}
System.out.println("sum=" + sum);

3.查找最大元素

int[] arrays = {1,2,3,4,5};
int max = arrays[0];
for (int i = 0; i < arrays.length; i++) {
    if(arrays[i] > max){
        max = arrays[i];
    }
}
System.out.println("max=" + max);

4.调用方法打印数组

public static void main(String[] args) {
    int[] arrays = {1,2,3,4,5};
    printArray(arrays);
}
public static void printArray(int[] arrays){
    for (int i = 0; i < arrays.length; i++) {
        System.out.println(arrays[i] + " ");
    }
}

5.调用方法反转数组并打印

public static void main(String[] args) {
    int[] arrays = {1,2,3,4,5};
    int[] reverse = reverse(arrays);
    printArray(reverse);
}
public static void printArray(int[] arrays){
    for (int i = 0; i < arrays.length; i++) {
        System.out.println(arrays[i] + " ");
    }
}
public static int[] reverse(int[] arrays) {
    int[] result = new int[arrays.length];
    for (int i = 0,j = result.length - 1; i < arrays.length; i++,j--) {
        result[j] = arrays[i];
    }
    return result;
}