Arrays and matrices and applications (java)

I. Tutorial Purpose

1. Understand the declaration, creation, initialization, and use of arrays in Java.

2. Understand the common methods for sorting arrays in Java.

3. Learn how to find a specific value in an array.

Ii. experiment content

This program will randomly generate 10 numbers (20-80) into the array, find the maximum number and its subscript.

Public class Array {public static void main (String agrs []) {int a [] = new int [10]; int I; for (I = 0; I <10; I ++) {a [I] = (int) (Math. random () * (50-20) + 20; System. out. print (a [I] + "");} System. out. println (); int max; int row; max = a [0]; row = 0; for (I = 1; I <10; I ++) {if (max
Running result





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VcD4KPHA + PGJyPgo8L3A + CjxwPjxwcmUgY2xhc3M9 "brush: java;">/*** use a random function to generate a 4 × 4 matrix (two-dimensional matrix) with an integer in the range of [20, 50, calculate the sum of the elements on the two diagonal lines. **/Public class exam7 {/*** @ param args */public static void main (String [] args) {// TODO Auto-generated method stubint sum = 0; int array [] [] = new int [4] [4]; for (int I = 0; I <4; I ++) {for (int j = 0; j <4; j ++) {array [I] [j] = (int) (Math. random () * (50-20) + 20); if (j % 4 = 0) System. out. println (); System. out. print ("" + array [I] [j]); if (I = j | I + j = 3) sum + = array [I] [j] ;}} System. out. println (); System. out. println ("sum of elements on the two diagonal lines: sum =" + sum );}}
  

Running result

// The output format is incorrect. It needs to be improved...

Package packagesevth;/** create and output a 10*10 matrix. The diagonal element of this matrix is 1, and the remaining elements are 0. Output this array. **/Public class array007 {/*** @ param args */public static void main (String [] args) {// TODO Auto-generated method stubint array [] [] = new int [10] [10]; for (int I = 0; I <10; I ++) {for (int j = 0; j <10; j ++) {if (I = j | I + j = 9) array [I] [j] = 1; elsearray [I] [j] = 0; if (j = 9) System. out. println (); System. out. print ("" + array [I] [j]) ;}}}

Running result

Package packageeight;/** the program will randomly generate 10 numbers (20-80) into the array, output the array, and then sort the array in ascending order, and output the sorted array. **/Public class arraysort {/*** @ param args */public static void main (String [] args) {// TODO Auto-generated method stubint array [] = new int [10]; int temp = 0; System. out. println ("array before sorting:"); for (int I = 0; I <10; I ++) {array [I] = (int) (Math. random () * (80-20) + 20); System. out. print ("" + array [I]);} System. out. println (); System. out. println ("sorted array:"); for (int I = 0; I <10; I ++) {for (int j = 0; j <10-i-1; j ++) {if (array [I]> array [I + 1]) {temp = array [I]; array [I] = array [I + 1]; array [I + 1] = temp;} System. out. print ("" + array [I]) ;}}

Running result