Java Academy · Lesson

Parsing Numbers from Input

Convert text to numbers.

Lines Are Always Strings

readLine() always gives you a String, even when the user types 42. To do math, you must parse that text into a number.

Java provides helper methods like Integer.parseInt and Double.parseDouble for exactly this.

Integer.parseInt(String) converts text like "42" into the int value 42.

Once parsed, you can add, multiply, or compare it like any number.

String text = "42";
int n = Integer.parseInt(text);
System.out.println(n + 1);