list to string java
La clase
ArrayList
es una matriz de tamaño variable, que se puede encontrar en el paquetejava.util
.
Usando +
Operador
- La forma más fácil de convertir un ArrayList a String es usar el operador plus
(+)
import java.util.ArrayList; import java.util.List; class Example { public static void main(String[] args) { List<String> countries = new ArrayList<>(); countries.add("Germany"); countries.add("Italy"); countries.add("Spain"); System.out.println(countries); StringBuilder str = new StringBuilder(); for (String country: countries) { str.append(country); str.append(" "); } System.out.println(str); } }
Salida
[Germany, Italy, Spain] Germany,Italy,Spain,
arraylist to string
Usando append()
Método
- Podemos usar el método
append()
de la claseStringBuilder
para convertirArrayList
en cadena.
import java.util.ArrayList; import java.util.List; class Example { public static void main(String[] args) { List<String> countries = new ArrayList<>(); countries.add("Germany"); countries.add("Italy"); countries.add("Spain"); System.out.println(countries); StringBuilder str = new StringBuilder(); for (String country: countries) { str.append(country); str.append(" "); } System.out.println(str); } }
Salida
[Germany, Italy, Spain] Germany Italy Spain
convert arraylist to string java
Usando join()
Método
join()
Método devuelve una cadena y se puede utilizar para convertirArrayList
aString
en Java.
import java.util.ArrayList; import java.util.List; class Example { public static void main(String[] args) { List<String> countries = new ArrayList<>(); countries.add("Germany"); countries.add("Italy"); countries.add("Spain"); System.out.println(countries); String str = String.join(",", countries); System.out.println(str); } }
Salida
[Germany, Italy, Spain] Germany,Italy,Spain
Usando replaceAll()
Método
- Con
replaceAll()
Método para sustituir corchetes de laLista
y luego convertir todos los elementos enString
Usando eltoString()
Método. - Difícil de usar
import java.util.ArrayList; import java.util.List; class Example { public static void main(String[] args) { List<String> countries = new ArrayList<>(); countries.add("Germany"); countries.add("Italy"); countries.add("Spain"); System.out.println(countries); String str = countries.toString().replaceAll("\\[|\\]", "").replaceAll(", ", ", "); System.out.println(str); } }
Salida
[Germany, Italy, Spain] Germany, Italy, Spain
Usando joining()
Método
- Puede utilizar el método
joining()
de la claseCollectors
para recopilar todos los elementos en un solo objeto String. - Esto añadido en la versión de Java 8
import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; class Example { public static void main(String[] args) { List<String> countries = new ArrayList<>(); countries.add("Germany"); countries.add("Italy"); countries.add("Spain"); System.out.println(countries); String str = Arrays.asList(countries).stream() .map(Object::toString) .collect(Collectors.joining(", ")); System.out.println(str); } }
Salida
[Germany, Italy, Spain] [Germany, Italy, Spain]
Usando deepToString()
Método
import java.util.ArrayList; import java.util.Arrays; import java.util.List; class Example { public static void main(String[] args) { List<String> countries = new ArrayList<>(); countries.add("Germany"); countries.add("Italy"); countries.add("Spain"); System.out.println(countries); String str = Arrays.deepToString(countries.toArray()); System.out.println(str); } }
Salida
[Germany, Italy, Spain] [Germany, Italy, Spain]