java数组的常用方法_JAVA_编程开发_程序员俱乐部

1.? 声明一个数组

Java代码

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String[] aArray = new String[5];
String[] bArray = {"a","b","c", "d", "e"};
String[] cArray = new String[]{"a","b","c","d","e"};

2.? 输出一个数组

Java代码

int[] intArray = { 1, 2, 3, 4, 5 };
String intArrayString = Arrays.toString(intArray);
 
// print directly will print reference value
System.out.println(intArray);
// [I@7150bd4d
 
System.out.println(intArrayString);
// [1, 2, 3, 4, 5]

3.? 从一个数组创建数组列表

Java代码

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String[] stringArray = { "a", "b", "c", "d", "e" };
ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));
System.out.println(arrayList);
// [a, b, c, d, e]

4.? 检查一个数组是否包含某个值

Java代码

String[] stringArray = { "a", "b", "c", "d", "e" };
boolean b = Arrays.asList(stringArray).contains("a");
System.out.println(b);
// true

5.? 连接两个数组

Java代码

int[] intArray = { 1, 2, 3, 4, 5 };
int[] intArray2 = { 6, 7, 8, 9, 10 };
// Apache Commons Lang library
int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2);

6.? 声明一个内联数组

Java代码

method(new String[]{"a", "b", "c", "d", "e"});

7.? 把提供的数组元素放入一个字符串

Java代码

// containing the provided list of elements
// Apache common lang
String j = StringUtils.join(new String[] { "a", "b", "c" }, ", ");
System.out.println(j);
// a, b, c

8.? 将一个数据列表转换为数组

Java代码

String[] stringArray = { "a", "b", "c", "d", "e" };
ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));
String[] stringArr = new String[arrayList.size()];
arrayList.toArray(stringArr);
for (String s : stringArr)
	System.out.println(s);

9.? 将一个数组转换为集（set）

Java代码

Set<String> set = new HashSet<String>(Arrays.asList(stringArray));
System.out.println(set);
//[d, e, b, c, a]

10.? 逆向一个数组

Java代码

int[] intArray = { 1, 2, 3, 4, 5 };
ArrayUtils.reverse(intArray);
System.out.println(Arrays.toString(intArray));
//[5, 4, 3, 2, 1]

11.? 移除数组中的元素

Java代码

int[] intArray = { 1, 2, 3, 4, 5 };
int[] removed = ArrayUtils.removeElement(intArray, 3);//create a new array
System.out.println(Arrays.toString(removed));

12.? 将整数转换为字节数组

Java代码

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2. ? ??
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5. }??