EN
Java - convert String to long
4 points
In Java, we can convert String to long in couple of different ways.
Short solutions:
xxxxxxxxxx1
// solution 12
long num1 = Long.parseLong("123"); // 1233
4
// solution 25
Long num2 = Long.valueOf("123"); // 123xxxxxxxxxx1
public class Example1 {2
3
public static void main(String[] args) {4
String str = "123";5
long num = Long.parseLong(str);6
System.out.println(num); // 1237
}8
}Output:
xxxxxxxxxx1
123xxxxxxxxxx1
public class Example2 {2
3
public static void main(String[] args) {4
String str = "123";5
Long num = Long.valueOf(str);6
System.out.println(num); // 1237
}8
}Output:
xxxxxxxxxx1
123xxxxxxxxxx1
public class Example3 {2
3
public static void main(String[] args) {4
5
// Long.parseLong() - returns long6
System.out.println(Long.parseLong("123")); // 1237
System.out.println(Long.parseLong("+123")); // 1238
System.out.println(Long.parseLong("-123")); // -1239
10
// Long.valueOf() - returns Long11
System.out.println(Long.valueOf("123")); // 12312
System.out.println(Long.valueOf("+123")); // 12313
System.out.println(Long.valueOf("-123")); // -12314
}15
}Output:
xxxxxxxxxx1
1232
1233
-1234
1235
1236
-123xxxxxxxxxx1
public class Example4 {2
3
public static void main(String[] args) {4
String str = "123a";5
long num = Long.parseLong(str);6
System.out.println(num);7
}8
}Output:
xxxxxxxxxx1
Exception in thread "main" java.lang.NumberFormatException: For input string: "123a"2
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)3
at java.lang.Long.parseLong(Long.java:589)4
at java.lang.Long.parseLong(Long.java:631)Both methods:
- Long.parseLong("123")
- Long.valueOf("123")
will throw java.lang.NumberFormatException if we try to parse anything else then:
digits or '+', '-' as first character.
