Java instance program for obtaining the length of an array (two-dimensional array)

This article describes how to obtain the length of an array (one-dimensional array, two-dimensional array length) in java.

We may know that js has a length function, and java also has a length function.

Example

If the array is data [], data. length

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Byte [] phone = new byte [81]; // create a byte array with a length of 81 Phone [I]! = 0 phone [I]! // The I position of the array is not equal to 0.

For example:

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Byte [] phone = new byte [81]; // create a byte array with a length of 81 Phone [1]! = 0 phone [1]! // The second value of the array is not equal to 0.

The following is an example:

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Public class StudyArrary { /** * @ Param args */ Public static void main (String [] args ){ // TODO Auto-generated method stub Byte [] phone = new byte [81]; // create a byte array with a length of 81 For (int a = 0; a <81; a ++) Phone [a] = (byte) a; // The I position of the array is not equal to 0. For (int I = 0; I <81; I ++ ){ If (phone [I]! = 0 ){ System. out. println ("phone [" + I + "] not equal to 0" + ", phone" + I + "is" + phone [I]); } Else System. out. println ("phone [" + I + "] equals 0" + ", phone" + I + "is" + phone [I]); } } }

Length of a two-dimensional array

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Public class Lesson { Public static void main (String [] args ){   // Two-dimensional array declaration method: // Data type [] [] array name = new data type [length] [length]; // Data type [] [] array name = {123}, {456 }}; Int [] [] num = new int [3] [3]; // defines a two-dimensional array with three rows and three columns. Num [0] [0] = 1; // assign a value to the first element of the first row Num [0] [1] = 2; // assign a value to the second element in the first row Num [0] [2] = 3; // assign a value to the third element in the first row Num [1] [0] = 4; // assign a value to the first element of the second row Num [1] [1] = 5; // assign a value to the second element in the second row Num [1] [2] = 6; // assign a value to the third element in the second row Num [2] [0] = 7; // assign a value to the first element of the third row Num [2] [1] = 8; // assign a value to the second element in the third row Num [2] [2] = 9; // assign a value to the third element in the third row For (int x = 0; x For (int y = 0; y System. out. print (num [x] [y]); } System. out. println ("/n "); } } }

// Array value arr [x] [y] indicates the value of column y in row x.
// When using a two-dimensional array object, pay attention to the length represented by length,
// Add length (such as arr. length) directly after the array name, which refers to rows );
// Specify the index with length (for example, arr [0]. length), which refers to the element owned by the row, that is, the number of columns.