To convert a string to an int value in Java, you can use the Integer.parseInt method. This method takes a string as an argument and returns the int value represented by that string.
Here's an example of how to use the Integer.parseInt method:
String s = "123"; int i = Integer.parseInt(s); // i is 123
Note that the Integer.parseInt method only works for strings that represent a valid int value. If the input string is empty or contains non-numeric characters, the Integer.parseInt method will throw a NumberFormatException.
Here's an example of how you can handle the NumberFormatException:
String s = "123";
try {
int i = Integer.parseInt(s);
} catch (NumberFormatException e) {
e.printStackTrace();
}
It's a good idea to handle this exception in a try-catch block, as shown in the example above, to avoid your program crashing if the input string is not a valid representation of an int value.
You can find more information about the Integer.parseInt method and examples of how to use it in the Java documentation.