Convert String to Integer in Java 8.

There is multiple way of Converting a String to Integer in Java 8.

• Create a Converter Functional Interface class method with input String and output Integer type.
• Inside convert method F is String and T as an Integer type.

Integer.parseInt() :-

• Integer::parseInt method use inside Converter interface for String to int type.
• a.convert() method converting the String to int and return the primitive int type.
• Print the output.

Integer.valueOf() :-

• Integer::ValueOf method use inside Converter interface for String to Integer Object type.
• a.convert() method converting the String to integer and return the integer Object type.
• Print the output.

@FunctionalInterface
interface Converter<F, T> {
	T convert(F from);
}

public class StringToInt {
	public static void main(String[] args) {
		
		Converter<String, Integer> a = Integer::parseInt;
		int d1 = a.convert("123");
		System.out.println("Using Integer parseInt method :- " + d1);

		Converter<String, Integer> b = Integer::valueOf;
		Integer d2 = b.convert("456");
		System.out.println("Using Integer valueOf method :- " + d2);
	}
}

Output :-
Using Integer parseInt method :- 123
Using Integer valueOf method :- 456