java - The method If(boolean) is undefined for the type

Question

Eclipse keeps giving me the following error:

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
input cannot be resolved
The method If(boolean) is undefined for the type bai1DinhLuatCuLong
Syntax error, insert ";" to complete Statement
F cannot be resolved to a variable

I do not understand this. What do I need to fix? Why can't I use the If() function?

I've tried looking through Google and Bing, and I've double checked my Java examples book, but I could not work this out.

import java.util.Scanner;


public class bai1DinhLuatCuLong
{
    public static void main(String[] args)
    { 
    System.out.print("Giá trì c?n tìm (F // q // r) : ");   
    char cantim = input.nextChar();

            // HERE THIS IS WHERE I PUT THE IF STATEMENT !!!
    If (cantim == 'F') {

        Scanner input = new Scanner(System.in); 
        System.out.print("?? l?n c?a ?i?n tích th? nh?t : ");
        double q1 = input.nextDouble();
        System.out.print("?? l?n c?a ?i?n tích th? hai : ");
        double q2 = input.nextDouble();
        System.out.print("Kho?ng cách gi?a 2 ?i?n tích : ");
        double r = input.nextDouble();
        System.out.print("H? s? k s? t? ??ng ???c ??t là 9*10^9 nh? trong h? SI");
        double F = 9 * Math.pow(10,9) * Math.abs(q1) * Math.abs(q2) / Math.pow(r,2);
    }

    System.out.print("?? l?n l?c t??ng tác gi?a 2 ?i?n tích ?i?m : " + "
 L?u y E là *10");

    }
}

Answer 1

If does not have a large cap I in java: it should be if.