The Nizi razred v paket java.util je del Ogrodje zbirke Java . Ta razred ponuja statične metode za dinamično ustvarjanje in dostop Java polja . Sestavljen je samo iz statičnih metod in metod razreda Object. Metode tega razreda lahko uporablja samo ime razreda.
Hierarhija razredov je naslednja:
java.lang.Object ? java.util.Arrays>
Geek, zdaj se zagotovo sprašujete, zakaj potrebujemo razred java Arrays, ko pa lahko deklariramo, inicializiramo in izračunamo operacije nad nizi. Odgovor na to pa leži v metodah tega razreda, o katerih bomo še razpravljali, saj praktično te funkcije pomagajo programerjem pri širjenju obzorij z nizi, na primer pogosto se zgodi, ko zanke se uporabljajo za izvajanje nekaterih nalog v matriki, kot so:
- Izpolnite matriko z določeno vrednostjo.
- Razvrsti nize.
- Iskanje v nizu.
- In še veliko več.
Tukaj razred Arrays ponuja več statičnih metod, ki jih je mogoče uporabiti za neposredno izvajanje teh nalog brez uporabe zank, zaradi česar je naša koda izjemno kratka in optimizirana.
Sintaksa: Izjava razreda
public class Arrays extends Object>
Sintaksa: Za uporabo nizov
Arrays.;>
Metode v razredu Java Array
Razred Arrays paketa java.util vsebuje več statičnih metod, ki jih je mogoče uporabiti za polnjenje, razvrščanje, iskanje itd. Zdaj pa razpravljajmo o metodah tega razreda, ki so spodaj prikazane v obliki tabele, kot sledi:
| Metode | Dejanje izvedeno |
|---|---|
| asList() | Vrne seznam fiksne velikosti, podprt z navedenimi nizi |
| binarySearch() | Išče navedeni element v matriki s pomočjo algoritma binarnega iskanja |
| binarySearch(matrika, fromIndex, toIndex, key, Comparator) | Išče obseg navedene matrike za navedeni predmet z algoritmom binarnega iskanja |
| primerjaj (niz 1, niz 2) | Leksikografsko primerja dve nizi, posredovani kot parametra. |
| copyOf(originalArray, newLength) | Kopira navedeno matriko, prirezuje ali zapolni s privzeto vrednostjo (če je potrebno), tako da ima kopija podano dolžino. |
| copyOfRange(originalArray, fromIndex, endIndex) | Kopira podani obseg navedene matrike v nove matrike. |
| deepEquals(Object[] a1, Object[] a2) | Vrne true, če sta podani matriki zelo enaki. |
| deepHashCode(Object[] a) | Vrne zgoščeno kodo na podlagi globoke vsebine podanih nizov. |
| deepToString(Object[] a) | Vrne nizovno predstavitev globoke vsebine navedenih matrik. |
| je enako (matrika1, matrika2) | Preveri, ali sta obe matriki enaki ali ne. |
| fill(originalArray, fillValue) | Dodeli to vrednost polnila vsakemu indeksu te matrike. |
| hashCode(originalArray) | Vrne celoštevilsko hashCode tega primerka matrike. |
| neujemanje (niz1, niz2) | Poišče in vrne indeks prvega neujemajočega se elementa med dvema podanima poljema. |
| parallelPrefix(originalArray, fromIndex, endIndex,functionOperator) | Izvede parallelPrefix za podani obseg matrike s podanim funkcijskim operatorjem. |
| parallelPrefix(originalArray, operator) | Izvede parallelPrefix za celotno matriko s podanim funkcijskim operatorjem. |
| parallelSetAll(originalArray,functionGenerator) | Nastavi vse elemente te matrike vzporedno z uporabo ponujene funkcije generatorja. |
| parallelSort(originalArray) | Razvrsti navedeno matriko z vzporednim razvrščanjem. |
| setAll(originalArray,functionGenerator) | Nastavi vse elemente navedene matrike z uporabo ponujene funkcije generatorja. |
| sort(originalArray) | Razvrsti celotno matriko v naraščajočem vrstnem redu. |
| sort(originalArray, fromIndex, endIndex) | Razvrsti podani obseg matrike v naraščajočem vrstnem redu. |
| sort(T[] a, int fromIndex, int toIndex, Comparator c) | Razvrsti podani obseg navedene matrike predmetov glede na vrstni red, ki ga sproži navedeni primerjalnik. |
| sort(T[] a, primerjalnik c) | Razvrsti podano matriko predmetov glede na vrstni red, ki ga povzroči navedeni primerjalnik. |
| spliterator(originalArray) | Vrne razdelilnik, ki pokriva vse podane matrike. |
| spliterator(originalArray, fromIndex, endIndex) | Vrne razdelilnik tipa matrike, ki pokriva podani obseg navedenih matrik. |
| tok (izvirna matrika) | Vrne zaporedni tok s podano matriko kot izvorom. |
| toString(originalArray) | Vrne nizovno predstavitev vsebine tega polja. Predstavitev niza je sestavljena iz seznama elementov matrike, zaprtih v oglatih oklepajih ([]). Sosednji elementi so ločeni z vejico, ki ji sledi presledek. Elementi se pretvorijo v nize kot s funkcijo String.valueOf(). |
Izvedba:
Primer 1: asList() Metoda
Java
// Java Program to Demonstrate Arrays Class> // Via asList() method> > // Importing Arrays utility class> // from java.util package> import> java.util.Arrays;> > // Main class> class> GFG {> > >// Main driver method> >public> static> void> main(String[] args)> >{> >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To convert the elements as List> >System.out.println(>'Integer Array as List: '> >+ Arrays.asList(intArr));> >}> }> |
>
>Izhod
Integer Array as List: [[I@2f4d3709]>
Primer 2: binarySearch() Metoda
Ta metoda išče podani element v matriki s pomočjo binarnega iskalnega algoritma.
Java
// Java Program to Demonstrate Arrays Class> // Via binarySearch() method> > // Importing Arrays utility class> // from java.util package> import> java.util.Arrays;> > // Main class> public> class> GFG {> > >// Main driver method> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >Arrays.sort(intArr);> > >int> intKey =>22>;> > >// Print the key and corresponding index> >System.out.println(> >intKey +>' found at index = '> >+ Arrays.binarySearch(intArr, intKey));> >}> }> |
>
>Izhod
22 found at index = 3>
Primer 3: binarySearch(matrika, fromIndex, toIndex, key, Comparator) Metoda
Ta metoda išče določen objekt v obsegu navedene matrike z algoritmom binarnega iskanja.
Java
// Java program to demonstrate> // Arrays.binarySearch() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >Arrays.sort(intArr);> > >int> intKey =>22>;> > >System.out.println(> >intKey> >+>' found at index = '> >+ Arrays> >.binarySearch(intArr,>1>,>3>, intKey));> >}> }> |
>
velikonočna jajca v androidu
>Izhod
22 found at index = -4>
Primer 4: primerjaj (niz 1, niz 2) Metoda
Java
// Java program to demonstrate> // Arrays.compare() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// Get the second Array> >int> intArr1[] = {>10>,>15>,>22> };> > >// To compare both arrays> >System.out.println(>'Integer Arrays on comparison: '> >+ Arrays.compare(intArr, intArr1));> >}> }> |
>
>Izhod
Integer Arrays on comparison: 1>
Primer 5: compareUnsigned(array 1, array 2) Metoda
Java
// Java program to demonstrate> // Arrays.compareUnsigned() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Arrays> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// Get the second Arrays> >int> intArr1[] = {>10>,>15>,>22> };> > >// To compare both arrays> >System.out.println(>'Integer Arrays on comparison: '> >+ Arrays.compareUnsigned(intArr, intArr1));> >}> }> |
>
>Izhod
Integer Arrays on comparison: 1>
Primer 6: metoda copyOf(originalArray, newLength).
Java
// Java program to demonstrate> // Arrays.copyOf() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To print the elements in one line> >System.out.println(>'Integer Array: '> >+ Arrays.toString(intArr));> > >System.out.println(>'
New Arrays by copyOf:
'>);> > >System.out.println(>'Integer Array: '> >+ Arrays.toString(> >Arrays.copyOf(intArr,>10>)));> >}> }> |
>
>Izhod
Integer Array: [10, 20, 15, 22, 35] New Arrays by copyOf: Integer Array: [10, 20, 15, 22, 35, 0, 0, 0, 0, 0]>
Primer 7: copyOfRange(originalArray, fromIndex, endIndex) Metoda
Java
// Java program to demonstrate> // Arrays.copyOfRange() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To print the elements in one line> >System.out.println(>'Integer Array: '> >+ Arrays.toString(intArr));> > >System.out.println(>'
New Arrays by copyOfRange:
'>);> > >// To copy the array into an array of new length> >System.out.println(>'Integer Array: '> >+ Arrays.toString(> >Arrays.copyOfRange(intArr,>1>,>3>)));> >}> }> |
>
>Izhod
Integer Array: [10, 20, 15, 22, 35] New Arrays by copyOfRange: Integer Array: [20, 15]>
Primer 8: deepEquals(Object[] a1, Object[] a2) Metoda
Java
// Java program to demonstrate> // Arrays.deepEquals() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Arrays> >int> intArr[][] = { {>10>,>20>,>15>,>22>,>35> } };> > >// Get the second Arrays> >int> intArr1[][] = { {>10>,>15>,>22> } };> > >// To compare both arrays> >System.out.println(>'Integer Arrays on comparison: '> >+ Arrays.deepEquals(intArr, intArr1));> >}> }> |
>
>Izhod
Integer Arrays on comparison: false>
Primer 9: metoda deepHashCode(Object[] a).
označevalni html
Java
// Java program to demonstrate> // Arrays.deepHashCode() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[][] = { {>10>,>20>,>15>,>22>,>35> } };> > >// To get the dep hashCode of the arrays> >System.out.println(>'Integer Array: '> >+ Arrays.deepHashCode(intArr));> >}> }> |
>
>Izhod
Integer Array: 38475344>
Primer 10: deepToString(Object[] a) Metoda
Java
// Java program to demonstrate> // Arrays.deepToString() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[][] = { {>10>,>20>,>15>,>22>,>35> } };> > >// To get the deep String of the arrays> >System.out.println(>'Integer Array: '> >+ Arrays.deepToString(intArr));> >}> }> |
>
>Izhod
Integer Array: [[10, 20, 15, 22, 35]]>
Primer 11: enako (matrika1, matrika2) Metoda
Java
// Java program to demonstrate> // Arrays.equals() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Arrays> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// Get the second Arrays> >int> intArr1[] = {>10>,>15>,>22> };> > >// To compare both arrays> >System.out.println(>'Integer Arrays on comparison: '> >+ Arrays.equals(intArr, intArr1));> >}> }> |
>
>Izhod
Integer Arrays on comparison: false>
Primer 12: fill(originalArray, fillValue) Metoda
Java
// Java program to demonstrate> // Arrays.fill() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Arrays> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >int> intKey =>22>;> > >Arrays.fill(intArr, intKey);> > >// To fill the arrays> >System.out.println(>'Integer Array on filling: '> >+ Arrays.toString(intArr));> >}> }> |
>
>Izhod
Integer Array on filling: [22, 22, 22, 22, 22]>
Primer 13: metoda hashCode(originalArray).
Java
// Java program to demonstrate> // Arrays.hashCode() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To get the hashCode of the arrays> >System.out.println(>'Integer Array: '> >+ Arrays.hashCode(intArr));> >}> }> |
>
>Izhod
Integer Array: 38475313>
Primer 14: mismatch(matrika1, matrika2) Metoda
Java
// Java program to demonstrate> // Arrays.mismatch() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Arrays> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// Get the second Arrays> >int> intArr1[] = {>10>,>15>,>22> };> > >// To compare both arrays> >System.out.println(>'The element mismatched at index: '> >+ Arrays.mismatch(intArr, intArr1));> >}> }> |
>
>Izhod
The element mismatched at index: 1>
Primer 15: metoda parallelSort(originalArray).
Java
// Java program to demonstrate> // Arrays.parallelSort() method> > // Importing Arrays class from> // java.util package> import> java.util.Arrays;> > // Main class> public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To sort the array using parallelSort> >Arrays.parallelSort(intArr);> > >System.out.println(>'Integer Array: '> >+ Arrays.toString(intArr));> >}> }> |
>
>Izhod
Integer Array: [10, 15, 20, 22, 35]>
Primer 16: sort(originalArray) Metoda
Java
tostring metoda java
// Java program to demonstrate> // Arrays.sort() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To sort the array using normal sort-> >Arrays.sort(intArr);> > >System.out.println(>'Integer Array: '> >+ Arrays.toString(intArr));> >}> }> |
>
>Izhod
Integer Array: [10, 15, 20, 22, 35]>
Primer 17: sort(originalArray, fromIndex, endIndex) Metoda
Java
// Java program to demonstrate> // Arrays.sort() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To sort the array using normal sort> >Arrays.sort(intArr,>1>,>3>);> > >System.out.println(>'Integer Array: '> >+ Arrays.toString(intArr));> >}> }> |
>
>Izhod
Integer Array: [10, 15, 20, 22, 35]>
Primer 18: sort(T[] a, int fromIndex, int toIndex, Comparator c) Metoda
Java
// Java program to demonstrate working of Comparator> // interface> import> java.util.*;> import> java.lang.*;> import> java.io.*;> > // A class to represent a student.> class> Student {> >int> rollno;> >String name, address;> > >// Constructor> >public> Student(>int> rollno, String name,> >String address)> >{> >this>.rollno = rollno;> >this>.name = name;> >this>.address = address;> >}> > >// Used to print student details in main()> >public> String toString()> >{> >return> this>.rollno +>' '> >+>this>.name +>' '> >+>this>.address;> >}> }> > class> Sortbyroll>implements> Comparator {> >// Used for sorting in ascending order of> >// roll number> >public> int> compare(Student a, Student b)> >{> >return> a.rollno - b.rollno;> >}> }> > // Driver class> class> Main {> >public> static> void> main(String[] args)> >{> >Student[] arr = {>new> Student(>111>,>'bbbb'>,>'london'>),> >new> Student(>131>,>'aaaa'>,>'nyc'>),> >new> Student(>121>,>'cccc'>,>'jaipur'>) };> > >System.out.println(>'Unsorted'>);> >for> (>int> i =>0>; i System.out.println(arr[i]); Arrays.sort(arr, 1, 2, new Sortbyroll()); System.out.println('
Sorted by rollno'); for (int i = 0; i System.out.println(arr[i]); } }> |
>
java tutorial za začetnike
>Izhod
Unsorted 111 bbbb london 131 aaaa nyc 121 cccc jaipur Sorted by rollno 111 bbbb london 131 aaaa nyc 121 cccc jaipur>
Primer 19: sort(T[] a, primerjalnik c) Metoda
Java
// Java program to demonstrate working of Comparator> // interface> import> java.util.*;> import> java.lang.*;> import> java.io.*;> > // A class to represent a student.> class> Student {> >int> rollno;> >String name, address;> > >// Constructor> >public> Student(>int> rollno, String name,> >String address)> >{> >this>.rollno = rollno;> >this>.name = name;> >this>.address = address;> >}> > >// Used to print student details in main()> >public> String toString()> >{> >return> this>.rollno +>' '> >+>this>.name +>' '> >+>this>.address;> >}> }> > class> Sortbyroll>implements> Comparator {> > >// Used for sorting in ascending order of> >// roll number> >public> int> compare(Student a, Student b)> >{> >return> a.rollno - b.rollno;> >}> }> > // Driver class> class> Main {> >public> static> void> main(String[] args)> >{> >Student[] arr = {>new> Student(>111>,>'bbbb'>,>'london'>),> >new> Student(>131>,>'aaaa'>,>'nyc'>),> >new> Student(>121>,>'cccc'>,>'jaipur'>) };> > >System.out.println(>'Unsorted'>);> >for> (>int> i =>0>; i System.out.println(arr[i]); Arrays.sort(arr, new Sortbyroll()); System.out.println('
Sorted by rollno'); for (int i = 0; i System.out.println(arr[i]); } }> |
>
>Izhod
Unsorted 111 bbbb london 131 aaaa nyc 121 cccc jaipur Sorted by rollno 111 bbbb london 121 cccc jaipur 131 aaaa nyc>
Primer 20: Metoda spliterator(originalArray).
Java
// Java program to demonstrate> // Arrays.spliterator() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To sort the array using normal sort> >System.out.println(>'Integer Array: '> >+ Arrays.spliterator(intArr));> >}> }> |
>
>Izhod
Integer Array: java.util.Spliterators$IntArraySpliterator@4e50df2e>
Primer 21: spliterator(originalArray, fromIndex, endIndex) Metoda
Java
// Java program to demonstrate> // Arrays.spliterator() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To sort the array using normal sort> >System.out.println(>'Integer Array: '> >+ Arrays.spliterator(intArr,>1>,>3>));> >}> }> |
>
>Izhod
Integer Array: java.util.Spliterators$IntArraySpliterator@4e50df2e>
Primer 22: Metoda stream(originalArray).
Java
// Java program to demonstrate> // Arrays.stream() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To get the Stream from the array> >System.out.println(>'Integer Array: '> >+ Arrays.stream(intArr));> >}> }> |
>
>Izhod
Integer Array: java.util.stream.IntPipeline$Head@7291c18f>
Primer 23: toString(originalArray) Metoda
Java
// Java program to demonstrate> // Arrays.toString() method> > import> java.util.Arrays;> > public> class> Main {> >public> static> void> main(String[] args)> >{> > >// Get the Array> >int> intArr[] = {>10>,>20>,>15>,>22>,>35> };> > >// To print the elements in one line> >System.out.println(>'Integer Array: '> >+ Arrays.toString(intArr));> >}> }> |
>
>Izhod
Integer Array: [10, 20, 15, 22, 35]>