Java Fundamentals Hardening 105: A summary of methods for printing arrays

1. Use the For loop to print the set of impressions.

2. Use the Arrays tool class to print the array into an ordered list.

3. Use the Arrays tool class to output the array contents using Arrays.tostring ().

The example code for the above three ways to print an array is as follows:

 PackageCom.himi.printarray;Importjava.util.Arrays; Public classAnormalarray { Public Static voidMain (string[] args) {/*** Print group with for Loop */String names[]= {"Georgianna", "Tenn", "Simon", "Tom" }; System.out.print ("[");  for(inti=0; i<names.length; i++) {            if(i== names.length-1) {System.out.print (Names[i]+"]"); } Else{System.out.print (names[i]+", ");                 }} System.out.println (); /*** use Arrays to convert an array to an ordered List print out * <String> list<String> Arrays.aslist (
     
      string. A)
     */System.out.println (arrays.aslist (names)); /*** use arrays.tostring to output array contents */System.out.println (arrays.tostring (names)); }}

Run the results as follows:

4. Use the Arrays tool class to print a 2-D array using arrays.deeptostring.

code example:

 PackageCom.himi.printarray;Importjava.util.Arrays;/** print array with arrays.deeptostring    */ Public classPrintArray { Public Static voidMain (string[] args) {//2d Array, need arrays.deeptostringstring[][] Deeparraystr =NewString[][] {{"Yiibai1", "Yiibai2"}, {"Yiibai3", "Yiibai4" } }; //Output: [[ljava.lang.string;@15db9742, [ljava.lang.string;@6d06d69c]System.out.println (arrays.tostring (DEEPARRAYSTR)); //Output: [[Yiibai1, Yiibai2], [Yiibai3, Yiibai4]]System.out.println (arrays.deeptostring (DEEPARRAYSTR)); //2d Array, need arrays.deeptostring        int[] Deeparrayint =New int[] {{1, 3, 5, 7, 9}, {2, 4, 6, 8, 10 } }; //Output: [[email protected], [[email protected]]System.out.println (arrays.tostring (deeparrayint)); //Output: [[1, 3, 5, 7, 9], [2, 4, 6, 8, ten]]System.out.println (arrays.deeptostring (deeparrayint)); }}

5. Using the tool class Gson (JSON parsing package developed by Google), convert the array to a JSON string to print out.

The code is as follows:

 PackageCom.himi.printarray;ImportCom.google.gson.Gson;/*** Print a JSON-formatted string. * @authorHebao **/ Public classPrintutils { Public Static voidMain (string[] args) {//TODO auto-generated Method Stub        intNumbers[] = {1,2,3,4,5,6,7}; String[] days= {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}; Gson Gson=NewGson (); String Numbersjson=Gson.tojson (numbers); String Daysjson=Gson.tojson (days); System.out.println ("numbers arrays into JSON data: "+Numbersjson); System.out.println ("Days array into JSON data: "+Daysjson); System.out.println (""); System.out.println ("-------Convert the JSON string to a string array-------"); String[] Weekdays= Gson.fromjson (Daysjson, string[].class);  for(inti=0; i<weekdays.length; i++) {            if(i = = Weekdays.length-1) {System.out.print (weekdays[i]); } Else{System.out.print (weekdays[i]+ ","); }} System.out.println (""); System.out.println ("-------Convert a multidimensional int array to a JSON-------"); int[] data = {{1, 2, 3}, {3, 4, 5}, {4, 5, 6}}; String JSON=Gson.tojson (data); System.out.println ("Data =" +JSON); System.out.println ("-------Convert the JSON string group into a multidimensional int array-------"); int[] DataMap = Gson.fromjson (JSON,int[][].class);  for(inti = 0; i < data.length; i++) {             for(intj = 0; J < Data[i].length; J + +) {System.out.print (Data[i][j]+ " "); } System.out.println (""); }    }}

The results of the program run as follows:

6. Using the stream to print an array, we can convert the array to a stream and print it out.

code example:

 PackageCom.himi.printarray;Importjava.util.Arrays;/** Use stream to print an array * We can convert it to a stream and print it out. */ Public classStreamarray { Public Static voidMain (string[] args) {//Arraystring[] Arraystr =Newstring[]{"Java", "Node", "Python", "Ruby"};        Arrays.stream (ARRAYSTR). ForEach (System.out::p rintln); int[] Arrayint = {1, 3, 5, 7, 9};        Arrays.stream (Arrayint). ForEach (System.out::p rintln); //2d Arraystring[][] Deeparraystr =Newstring[][]{{"Yiibai1", "Yiibai2"}, {"Yiibai3", "Yiibai4"} }; Arrays.stream (DEEPARRAYSTR). FLATMAP (x-Arrays.stream (x)). ForEach (System.out::p rintln); int[] Deeparrayint =New int[][]{{1, 3, 5, 7, 9}, {2, 4, 6, 8, 10}}; Arrays.stream (Deeparrayint). Flatmaptoint (x-Arrays.stream (x)). ForEach (System.out::p rintln); }}

The results of the program run as follows:

Java Fundamentals Hardening 105: A summary of methods for printing arrays