Detailed explanation of the simple definition and use of two-dimensional arrays in Java

This article mainly introduces the simple definition and usage of Java two-dimensional array. It briefly analyzes the definition, usage and related precautions of Java two-dimensional array in the form of examples. Friends in need can refer to it

The examples in this article describe the simple definition and use of Java two-dimensional arrays. Share it with everyone for your reference, the details are as follows:

Java's two-dimensional array first creates a one-dimensional array, and then the elements of the array reference another one-dimensional array. When using a two-dimensional array, use two square brackets [] to access the reference of each dimension until the final data is accessed.

public class MultiDimArray{
/**
* @param args
*/
  public static void main(String[] args) {
    int[][] arr = new int[3][];
    arr[0] = new int[] { 1 };
    arr[1] = new int[] { 1, 2, 3 };
    arr[2] = new int[] { 3, 4 };
    for (int[] a : arr) {
      for (int i : a) {
        System.out.print(i + " ");
      }
      System.out.println();
    }
  }
}

In the above code, when instantiating the two-dimensional array, the length of the second dimension is not specified, and there is no need to specify it, because their lengths can be different. . The length of arr.length in the above example is 3, but the length of arr[i].length is uncertain. The output result is as follows:

1
1 2 3
3 4

The length of a Java array can be dynamically changed. Programmers can arbitrarily expand the dimensions of the array, and the number of elements in each dimension can be unlimited. same.

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