java Arrays工具类常用十大方法
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Arrays工具类十大常用方法
原文链接:http://blog.csdn.net/renfufei/article/details/16829457
0. 声明数组
String[] aArray = new String[5]; String[] bArray = {"a","b","c", "d", "e"}; String[] cArray = new String[]{"a","b","c","d","e"};
1. 打印数组
int[] intArray = { 1, 2, 3, 4, 5 }; String intArrayString = Arrays.toString(intArray); // 直接打印,则会打印出引用对象的Hash值 // [I@7150bd4d System.out.println(intArray); // [1, 2, 3, 4, 5] System.out.println(intArrayString);
2. 根据数组创建ArrayList
String[] stringArray = { "a", "b", "c", "d", "e" }; ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray)); // [a, b, c, d, e] System.out.println(arrayList);
3. 检查数组是否包含某个值
String[] stringArray = { "a", "b", "c", "d", "e" }; boolean b = Arrays.asList(stringArray).contains("a"); // true System.out.println(b);
4. 合并连接两个数组
int[] intArray = { 1, 2, 3, 4, 5 }; int[] intArray2 = { 6, 7, 8, 9, 10 }; // Apache Commons Lang 库 int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2);
5. 声明内联数组
method(new String[]{"a", "b", "c", "d", "e"});
6. 用给定的字符串连结(join)数组
// containing the provided list of elements // Apache common lang String j = StringUtils.join(new String[] { "a", "b", "c" }, ", "); // a, b, c System.out.println(j);
7. 将ArrayList转换为数组
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. 将数组转换为Set
Set<String> set = new HashSet<String>(Arrays.asList(stringArray)); //[d, e, b, c, a] System.out.println(set);
9. 数组元素反转
int[] intArray = { 1, 2, 3, 4, 5 }; ArrayUtils.reverse(intArray); //[5, 4, 3, 2, 1] System.out.println(Arrays.toString(intArray));
10. 移除元素
int[] intArray = { 1, 2, 3, 4, 5 }; int[] removed = ArrayUtils.removeElement(intArray, 3);//创建新的数组 System.out.println(Arrays.toString(removed));
更多——转换int值为字节数组
byte[] bytes = ByteBuffer.allocate(4).putInt(8).array(); for (byte t : bytes) { System.out.format("0x%x ", t); }
标签:java,String,十大,Arrays,System,intArray,println,out 来源: https://www.cnblogs.com/j99426/p/15467399.html