
How to convert String to Int in Java
Converting a String to Int in Java is a common scenario which we face everyday.Now this can be achieved in multiple ways.
Integer.parseInt()
Integer.parseInt() returns a primitive int datatype.
String num = "12345";
int number = 0;
try {
number = Integer.parseInt(num);
}
catch (NumberFormatException e) {
}
Integer.valueOf()
The Integer.valueOf() method returns an cached instance of java.lang.Integer.
String num = "12345";
Integer number = 0;
try {
number = Integer.valueOf(num);
}
catch (NumberFormatException e) {
}
Integer.decode()
This basically decodes a String into an Integer.It returns a wrapper object of type java.lang.Integer.
It accepts Strings in the formats like DecimalNumeral, HexDigits, and OctalDigits.
DecimalNumeral, HexDigits, and OctalDigits are as defined in section 3.10.1 of The Java™ Language
Specification, except that underscores are not accepted between digits.
String num = "12345";
Integer number = 0;
try {
number = Integer.decode(num);
}
catch (NumberFormatException e) {
}
Integer.decode() for Octal numbers
String num = "022";
Integer number = 0;
try {
number = Integer.decode(num); //18
}
catch (NumberFormatException e) {
}
Integer.decode() for Hexadecimal numbers
String num = "0X12A";
Integer number = 0;
try {
number = Integer.decode(num); //298
}
catch (NumberFormatException e) {
}

