今天总结数组方面的东西,搜集了些好的东东跟大家分享下,以后开发可能用的到的,快来看看吧!
数组工具类中的几个方法
1. 在Java中输出一个数组(Print an array in Java)
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]
2. 从数组中创建数组列表(Create an ArrayList from an array)
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]
3. 检查数组中是否包含特定值(Check if an array contains a certain value)
String[] stringArray = { "a", "b", "c", "d", "e" };
boolean b = Arrays.asList(stringArray).contains("a");
System.out.println(b);
// true
4. 连接两个数组( Concatenate two arrays)
int[] intArray = { 1, 2, 3, 4, 5 };
int[] intArray2 = { 6, 7, 8, 9, 10 };
// Apache Commons Lang library
int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2);
5. 声明一个数组内链(Declare an array inline )
method(new String[]{"a", "b", "c", "d", "e"});
6. 将数组元素加入到一个独立的字符串中(Joins the elements of the provided array into a single String)
<span style="font-size:12px;">String j = StringUtils.join(new String[] { "a", "b", "c" }, ", ");
System.out.println(j);
// a, b, c </span>
7. 将数组列表转换成一个数组 (Covnert an ArrayList to an array)
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);
8. 将数组转换成一个集合(Convert an array to a set)
Set<String> set = new HashSet<String>(Arrays.asList(stringArray));
System.out.println(set);
//[d, e, b, c, a]
9. 数组反转(Reverse an array)
int[] intArray = { 1, 2, 3, 4, 5 };
ArrayUtils.reverse(intArray);
System.out.println(Arrays.toString(intArray));
//[5, 4, 3, 2, 1]
10. 删除数组元素(Remove element of an array)
<span style="font-size:12px;">int[] intArray = { 1, 2, 3, 4, 5 };
int[] removed = ArrayUtils.removeElement(intArray, 3);//create a new array
System.out.println(Arrays.toString(removed)); </span>
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