Java compiler not checking IF ELSE condition beforehand (or at least I think that is what's happening...)

Question

I have a simple class file called File.java with 3 functions in it: createFile, writeContent and the obligatory main function as a driver:

import java.io.*;

class CreateFile {

    public static boolean createFile(File file, String fileName) throws IOException {
        if (file.createNewFile()){
            System.out.println(fileName + ": File created successfully!");
            return false;
        } else {
            System.out.println(fileName + ": File already existing!");
            return true;
        }
    }

    public static void writeContent(String fileName, String fileContent, boolean append) throws IOException {
        if (append = false) {
            BufferedWriter writer = new BufferedWriter(new FileWriter(fileName, false));
        } else {
            BufferedWriter writer = new BufferedWriter(new FileWriter(fileName, true));
        }
        writer.write(fileContent);
        writer.close();
    }

    public static void main(String[] args) throws IOException {

        String fileName = "file.txt";
        File file = new File(fileName);
        boolean append = createFile(file, fileName);
        String fileContent = "Hello, this is a test";
        writeContent(fileName, fileContent, append);
    }
}

The trouble is with the function writeContent, which is called in the last line. There is a basic if condition, checking whether the writing process needs to append to the file, or not (I know this is not necessary, but I am still testing, so bear with me).

I get an error saying the compiler can't find the symbol writer, meaning that the BufferedWriter writer is created before checking the if condition. This is precisely what I don't get: Why isn't the if condition executed beforehand?

If I include the write commands in the if and the else statement it works beautifully, but that causes code redundancy which is what I am trying to circumvent:

    public static void writeContent(String fileName, String fileContent, boolean append) throws IOException {
        if (append = false) {
            BufferedWriter writer = new BufferedWriter(new FileWriter(fileName, false));
            writer.write(fileContent);
            writer.close();
        } else {
            BufferedWriter writer = new BufferedWriter(new FileWriter(fileName, true));
            writer.write(fileContent);
            writer.close();
        }
    }

I am sure I am simply obtuse to something fundamental & simple - would you mind giving me a hint here?

Answer 1

Change this:

if (append = false) {
    BufferedWriter writer = new BufferedWriter(new FileWriter(fileName, false));
} else {
    BufferedWriter writer = new BufferedWriter(new FileWriter(fileName, true));
}

Change to:

BufferedWriter writer;
if (append == false) {
    writer = new BufferedWriter(new FileWriter(fileName, false));
} else {
    writer = new BufferedWriter(new FileWriter(fileName, true));
}

If you create variable inside braces {} it's scope is limited to them. So, you should create writer outside if, because you use it later.