which way is the best way to use the Scanner in JAVA?? using try or public static?? forget the spanish sentences I just want to know how to use the Scanner
#about Scanner
near cape
simple joltBOT
Hey, @near cape!
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near cape
which way is the best way to use the Scanner in JAVA?? using try or public static?? forget the spanish sentences I just want to know how to use the Scanner
molten pond
Any object should be scoped to it's part in the program, method, class, etc.
Line 19 should not be used, the Scanner should be declared on line 17
near cape
declared like this? --> Scanner teclado = new Scanner(System.in) without try(){} ??
molten pond
yes
molten pond
On line 27 do: teclado.close();
near cape
molten pond
no more error?
near cape
okay now imagine that I want to repeat this program 5 times without clicking the running buttom
molten pond
use a for loop
near cape
no more error?
nope but, let me show you
near cape
use a ``for loop``
can I do it with for ?
molten pond
yes, 100%
molten pond
for(int i = 0; i < 4; i++) {
//code here
}
Make sure to declare Scanner, and .close() it outside the loop
near cape
that's my real problem, I can't use teclado.close(); because I want to loop the program 5 times
near cape
Make sure to declare ``Scanner``, and ``.close()`` it outside the loop
okay my bad
let me fix
molten pond
lol
Scanner teclado = new Scanner(System.in);
byte edad;
String respuesta;
for(int i = 0; i < 4; i++) {
//code here
}
teclado.close();
okay It works, so this is the best way to use the Scanner in JAVA??
before you go let me show you something
molten pond
in this instance, yes
near cape
in this instance, yes
because some times it's better using the public static or try(){} right?
molten pond
you should need to rarely use try
unless you're dealing with files or fetching, etc.
near cape
I was using try in cousin numbers program look
/*
* 2.- Un número es primo si solo tiene dos divisores: el 1 y el propio número.
* Implementa un programa Java que pida por teclado 5 números. Para cada uno de ellos:
*
* - Comprueba si es negativo. En caso afirmativo, muestra el mensaje por pantalla "El número es negativo".
* - Si es positivo, deberá mostrar por pantalla si es primo o no.
* - Procesados los 5 números, el programa finaliza.
*/
import java.util.Scanner;
/**
*
* @author Francisco José Rodríguez Afonso
*/
public class PROG04_Ejerc2 {
public static void main(String[] args) {
Scanner teclado = new Scanner(System.in);
for (int i = 0; i < 5; i++) {
int num;
int detectar = 0;
System.out.print("\nIntroduce un número: ");
num = teclado.nextInt();
if (num < 0) {
System.out.println("El número es negativo.");
} else {
for (int j = 1; j <= num; j++) {
if (num % j == 0) detectar++;
}
if (detectar == 2) {
System.out.println("El número " + num + " es primo.");
} else {
System.out.println("El número " + num + " no es primo.");
}
}
}
teclado.close();
System.out.println("\nPrograma finalizado.\n");
}
}
/*
* 2.- Un número es primo si solo tiene dos divisores: el 1 y el propio número.
* Implementa un programa Java que pida por teclado 5 números. Para cada uno de ellos:
*
* - Comprueba si es negativo. En caso afirmativo, muestra el mensaje por pantalla "El número es negativo".
* - Si es positivo, deberá mostrar por pantalla si es primo o no.
* - Procesados los 5 números, el programa finaliza.
*/
import java.util.Scanner;
/**
*
* @author Francisco José Rodríguez Afonso
*/
public class PROG04_Ejerc2 {
public static void main(String[] args) {
try (Scanner teclado = new Scanner(System.in)) {
for (int i = 0; i < 5; i++) {
int num;
int detectar = 0;
System.out.print("\nIntroduce un número: ");
num = teclado.nextInt();
if (num < 0) {
System.out.println("El número es negativo.");
} else {
for (int j = 1; j <= num; j++) {
if (num % j == 0) detectar++;
}
if (detectar == 2) {
System.out.println("El número " + num + " es primo.");
} else {
System.out.println("El número " + num + " no es primo.");
}
}
}
}
System.out.println("\nPrograma finalizado.\n");
}
}
is better to use the .close() for the moment with those programs right?
near cape
thank you very much for your time, I really needed an answer for this and you gave me one, now I understand this better, I'm new in programming and I have a lot of things to learn, thank you 
molten pond
of course! my pleasure 🙂