Javassa a merkkijono on esine joka edustaa merkkijonoa. Jotta voisimme käyttää Strings-toimintoa, meidän on tuotava merkkijono kohdassa määritelty luokka java.lang paketti. The Merkkijonotaulukko on joukko kieleistä, joilla on kiinteä pituus. Tässä osiossa opimme miten merkkijono muunnetaan merkkijonoksi .

Huomautus: Java-merkkijonot ovat muuttumattomia objekteja, eli merkkijonon arvoa ei voi muuttaa, kun se on luotu.

Merkkijonon muuntaminen merkkijonotaulukoksi

On neljä tapaa muuntaa merkkijono merkkijonoksi Javassa:

java on sama

1. String.split()-menetelmän käyttäminen
2. Pattern.split()-menetelmän käyttäminen
3. String[ ] -menetelmän käyttäminen
4. ToArray()-menetelmän käyttäminen

String.split()-menetelmän käyttäminen

The String.split() menetelmää käytetään merkkijonon jakamiseen yksittäisiksi merkkijonokokonaisuuksiksi annetun erottimen (välilyönti tai muut symbolit) perusteella. Voimme tallentaa nämä entiteetit suoraan merkkijonotaulukkoon.

Tarkastellaan seuraavaa esimerkkiä, jossa käytämme String.split()-menetelmää merkkijonon muuntamiseen merkkijonotaulukoksi.

TestSplitMethod.java

 public class TestSplitMethod { public static void main(String[] args) { //declaring and initializing a string String str = &apos;Converting string to string array using split() method&apos;; //declaring an empty string array String[] strArray = null; //converting using String.split() method with whitespace as a delimiter strArray = str.split(&apos; &apos;); //printing the converted string array for (int i = 0; i<strarray.length; i++){ system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java.webp" alt="How to convert String to String array in Java"> <p> <strong>Example 2:</strong> </p> <p>In the following example, we have converted the string to a string array based on the delimiter that is a <strong>,</strong> (comma).</p> <p> <strong>TestSplitMethod2.java</strong> </p> <pre> public class TestSplitMethod2 { public static void main(String[] args) { String commaSeparatedStr = &apos;Hello,have,a,nice,day&apos;; String[] strArray = null; //empty string array //converting using String.split() method with comma as a delimiter strArray = commaSeparatedStr.split(&apos;,&apos;); //printing the converted string array for (int i = 0; i<strarray.length; i++){ system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-2.webp" alt="How to convert String to String array in Java"> <h3>Using Pattern.split() Method</h3> <p>The Pattern.split() method is used to split the string into an array of strings with the help of regular expression (pattern) as the delimiter.</p> <p>In order to use the method, we need to import the <strong>Pattern</strong> class in our Java code as:</p> <pre> import java.util.regex.Pattern; </pre> <p>Let&apos;s consider the following example where we split a string into an array by using the delimiter as whitespace.</p> <p> <strong>SplitMethodOfPatternClass.java</strong> </p> <pre> //importing Pattern class import java.util.regex.Pattern; public class SplitMethodOfPatternClass { public static void main(String[] args) { //declaring and initializing a string String str = &apos;Converting string to string array using Pattern.split()&apos;; //declaring an empty string array String[] strArray = null; //parsing white space as a parameter Pattern ptr = Pattern.compile(&apos; &apos;); //storing the string elements in array after splitting strArray = ptr.split(str); //printing the converted string array for (int i = 0; i<strarray.length; i++){ system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-3.webp" alt="How to convert String to String array in Java"> <p> <strong>Example 2:</strong> </p> <p>We can also split a string into an array by using any string or pattern as a delimiter. Here, we have used the delimiter <strong>#a1.</strong> </p> <p> <strong>SplitMethodOfPatternClass2.java</strong> </p> <pre> //importing Pattern class import java.util.regex.Pattern; public class SplitMethodOfPatternClass2 { public static void main(String[] args) { //declaring and initializing a string with a separator String str = &apos;Hello #a1Ben #a1how #a1are #a1you ?&apos;; //declaring an empty string array String[] strArray = null; //splitting the string with delimiter as #a1 String patternStr = &apos;#a1&apos;; Pattern ptr = Pattern.compile(patternStr); //storing the string elements in array after splitting strArray = ptr.split(str); //printing the converted string array for (int i = 0; i<strarray.length; i++){ system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-4.webp" alt="How to convert String to String array in Java"> <p>The above example splits the single string into five separate strings based on the delimiter #a1. The parts of the string that matched the delimiter are not included in the array.</p> <h3>Using String[ ] Approach</h3> <p>We can simply convert string to string array by using the string index [ ]. Here, we pass the string to <strong>String [ ] {}.</strong> </p> <p>Consider the following example where we have used the String[] to convert a string into a string array.</p> <p> <strong>StrToStrArray.java</strong> </p> <pre> import java.util.Arrays; public class StrToStrArray { public static void main(String[] args) { //declaring and initializing a string String str = &apos;Converting string to string array using String[]&apos;; //passing the string to String[] {} String[] strArray = new String[] {str}; //printing the string array using Arrays.toString() System.out.println(Arrays.toString(strArray)); } } </pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-5.webp" alt="How to convert String to String array in Java"> <h3>Using toArray() Method</h3> <p>We can also convert String to String array by using the <a href="/java-list-toarray-method">toArray()</a> method of the <a href="/java-list">List</a> class. It takes a list of type String as the input and converts each entity into a string array.</p> <p>Consider the following example where we have converted the list of strings into a string array.</p> <p> <strong>StringListtoArray.java</strong> </p> <pre> //importing ArrayList and List class import java.util.ArrayList; import java.util.List; public class StringListtoArray { public static void main(String[] args) { //creating a list of type string List list = new ArrayList (); //adding elements to list list.add(&apos;Hello&apos;); list.add(&apos;Welcome&apos;); list.add(&apos;To&apos;); list.add(&apos;Tutorial&apos;); //size of list int list_size = list.size(); //creating string array String[] strArray = new String[list_size]; //converting to string array list.toArray(strArray); //printing the string array for(int i = 0; i <strarray.length; i++) { system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-6.webp" alt="How to convert String to String array in Java"> <hr></strarray.length;></pre></strarray.length;></pre></strarray.length;></pre></strarray.length;></pre></strarray.length;>

Tarkastellaan seuraavaa esimerkkiä, jossa jaetaan merkkijono taulukoksi käyttämällä erotinta välilyöntinä.

kokonaisluku merkkijonoksi javassa

SplitMethodOfPatternClass.java

 //importing Pattern class import java.util.regex.Pattern; public class SplitMethodOfPatternClass { public static void main(String[] args) { //declaring and initializing a string String str = &apos;Converting string to string array using Pattern.split()&apos;; //declaring an empty string array String[] strArray = null; //parsing white space as a parameter Pattern ptr = Pattern.compile(&apos; &apos;); //storing the string elements in array after splitting strArray = ptr.split(str); //printing the converted string array for (int i = 0; i<strarray.length; i++){ system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-3.webp" alt="How to convert String to String array in Java"> <p> <strong>Example 2:</strong> </p> <p>We can also split a string into an array by using any string or pattern as a delimiter. Here, we have used the delimiter <strong>#a1.</strong> </p> <p> <strong>SplitMethodOfPatternClass2.java</strong> </p> <pre> //importing Pattern class import java.util.regex.Pattern; public class SplitMethodOfPatternClass2 { public static void main(String[] args) { //declaring and initializing a string with a separator String str = &apos;Hello #a1Ben #a1how #a1are #a1you ?&apos;; //declaring an empty string array String[] strArray = null; //splitting the string with delimiter as #a1 String patternStr = &apos;#a1&apos;; Pattern ptr = Pattern.compile(patternStr); //storing the string elements in array after splitting strArray = ptr.split(str); //printing the converted string array for (int i = 0; i<strarray.length; i++){ system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-4.webp" alt="How to convert String to String array in Java"> <p>The above example splits the single string into five separate strings based on the delimiter #a1. The parts of the string that matched the delimiter are not included in the array.</p> <h3>Using String[ ] Approach</h3> <p>We can simply convert string to string array by using the string index [ ]. Here, we pass the string to <strong>String [ ] {}.</strong> </p> <p>Consider the following example where we have used the String[] to convert a string into a string array.</p> <p> <strong>StrToStrArray.java</strong> </p> <pre> import java.util.Arrays; public class StrToStrArray { public static void main(String[] args) { //declaring and initializing a string String str = &apos;Converting string to string array using String[]&apos;; //passing the string to String[] {} String[] strArray = new String[] {str}; //printing the string array using Arrays.toString() System.out.println(Arrays.toString(strArray)); } } </pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-5.webp" alt="How to convert String to String array in Java"> <h3>Using toArray() Method</h3> <p>We can also convert String to String array by using the <a href="/java-list-toarray-method">toArray()</a> method of the <a href="/java-list">List</a> class. It takes a list of type String as the input and converts each entity into a string array.</p> <p>Consider the following example where we have converted the list of strings into a string array.</p> <p> <strong>StringListtoArray.java</strong> </p> <pre> //importing ArrayList and List class import java.util.ArrayList; import java.util.List; public class StringListtoArray { public static void main(String[] args) { //creating a list of type string List list = new ArrayList (); //adding elements to list list.add(&apos;Hello&apos;); list.add(&apos;Welcome&apos;); list.add(&apos;To&apos;); list.add(&apos;Tutorial&apos;); //size of list int list_size = list.size(); //creating string array String[] strArray = new String[list_size]; //converting to string array list.toArray(strArray); //printing the string array for(int i = 0; i <strarray.length; i++) { system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-6.webp" alt="How to convert String to String array in Java"> <hr></strarray.length;></pre></strarray.length;></pre></strarray.length;>

Lähtö:

ToArray()-menetelmän käyttäminen

Voimme myös muuntaa merkkijonon String-taulukoksi käyttämällä toArray() menetelmä Lista luokkaa. Se ottaa syötteeksi luettelon, jonka tyyppi on String, ja muuntaa jokaisen entiteetin merkkijonotaulukoksi.

Tarkastellaan seuraavaa esimerkkiä, jossa olemme muuntaneet merkkijonoluettelon merkkijonotaulukoksi.

StringListoArray.java

 //importing ArrayList and List class import java.util.ArrayList; import java.util.List; public class StringListtoArray { public static void main(String[] args) { //creating a list of type string List list = new ArrayList (); //adding elements to list list.add(&apos;Hello&apos;); list.add(&apos;Welcome&apos;); list.add(&apos;To&apos;); list.add(&apos;Tutorial&apos;); //size of list int list_size = list.size(); //creating string array String[] strArray = new String[list_size]; //converting to string array list.toArray(strArray); //printing the string array for(int i = 0; i <strarray.length; i++) { system.out.println(strarray[i]); } < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/java-tutorial/38/how-convert-string-string-array-java-6.webp" alt="How to convert String to String array in Java"> <hr></strarray.length;>