本文分享了关于Java数组最顶级的11大方法,帮助你解决工作流程问题,无论是运用在团队环境或是在私人项目中,你都可以直接拿来用!
0. 声明一个数组(Declare an array)
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1.String[] aArray = new String[5];
2.String[] bArray = {"a","b","c", "d", "e"};
3.String[] cArray = new String[]{"a","b","c","d","e"};
1. 在Java中输出一个数组(Print an array in Java)
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1.int[] intArray = { 1, 2, 3, 4, 5 };
2.String intArrayString = Arrays.toString(intArray);
3.
4.// print directly will print reference value
5.System.out.println(intArray);
6.// [I@7150bd4d
7.
8.System.out.println(intArrayString);
9.// [1, 2, 3, 4, 5]
2. 从数组中创建数组列表(Create an ArrayList from an array)
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1.String[] stringArray = { "a", "b", "c", "d", "e" };
2.ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));
3.System.out.println(arrayList);
4.// [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)
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1.String[] stringArray = { "a", "b", "c", "d", "e" };
2.boolean b = Arrays.asList(stringArray).contains("a");
3.System.out.println(b);
4.// true
4. 连接两个数组( Concatenate two arrays)
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1.int[] intArray = { 1, 2, 3, 4, 5 };
2.int[] intArray2 = { 6, 7, 8, 9, 10 };
3.// Apache Commons Lang library
4.int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2);
5. 声明一个数组内链(Declare an array inline )
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1.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)
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1.// containing the provided list of elements
2.// Apache common lang
3.String j = StringUtils.join(new String[] { "a", "b", "c" }, ", ");
4.System.out.println(j);
5.// a, b, c
7. 将数组列表转换成一个数组 (Covnert an ArrayList to an array)
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1.String[] stringArray = { "a", "b", "c", "d", "e" };
2.ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));
3.String[] stringArr = new String[arrayList.size()];
4.arrayList.toArray(stringArr);
5.for (String s : stringArr)
6. System.out.println(s);
8. 将数组转换成一个集合(Convert an array to a set)
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1.Set<String> set = new HashSet<String>(Arrays.asList(stringArray));
2.System.out.println(set);
3.//[d, e, b, c, a]
9. 反向数组(Reverse an array)
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1.int[] intArray = { 1, 2, 3, 4, 5 };
2.ArrayUtils.reverse(intArray);
3.System.out.println(Arrays.toString(intArray));
4.//[5, 4, 3, 2, 1]
10. 删除数组元素(Remove element of an array)
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1.int[] intArray = { 1, 2, 3, 4, 5 };
2.int[] removed = ArrayUtils.removeElement(intArray, 3);//create a new array
3.System.out.println(Arrays.toString(removed));
One more – convert int to byte array
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1.byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();
2.
3.for (byte t : bytes) {
4. System.out.format("0x%x ", t);
5.}
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