设置默认值时需要这个吗？

Question

我是JavaScript新手。我正在阅读一个简洁的ES6功能，destructuring assignment。在＆＃34;设置功能参数的默认值 - ES6版本＆＃34;它有以下例子：

Scanner fileReader = new Scanner(new FileReader("pets.txt"));
    fileReader.useLocale(Locale.US);

    double age = 0, weight = 0;
    int counter = 0;

    // A while loop to read until there are no more lines
    while(fileReader.hasNext()) {
        fileReader.useDelimiter(",");
        System.out.println(fileReader.next());
        System.out.println(fileReader.nextInt());
        fileReader.useDelimiter(Pattern.compile("[\\r\\n,]+"));
        System.out.println(fileReader.nextDouble());

    }

    fileReader.close();

在解构function drawES6Chart({size = 'big', cords = { x: 0, y: 0 }, radius = 25} = {}) { //------------------------------------------------------ what is this for? ^ } drawES6Chart({ cords: { x: 18, y: 30 }, radius: 30 }); 的参数时drawES6Chart()的目的是什么？