的CoffeeScript - 數組初始化

Question

我有以下的代碼，明顯的作品，但我相當肯定存在的CoffeeScript表達這種更簡潔的方式：

todos = [] 

    for i in [1..10]                    
    todos.push App.store.find App.Todo, i 

Answer 1

todos = (App.store.find(App.Todo, i) for i in [1..10]) 

的圓括號表示list comprehension，這將返回值收集到數組中並返回。

考慮下面的兩個例子。封閉的圓括號改變了Coffeescript解釋循環的方式。

# With parentheses (list comprehension) 
todos = (App.store.find(App.Todo, i) for i in [1..10]) 

# Without parentheses (plain old loop) 
todos = App.store.find(App.Todo, i) for i in [1..10] 

和輸出：

// With parentheses 
todos = (function() { 
    var _i, _results; 
    _results = []; 
    for (i = _i = 1; _i <= 10; i = ++_i) { 
    _results.push(App.store.find(App.Todo, i)); 
    } 
    return _results; 
})(); 

// Without parentheses 
for (i = _i = 1; _i <= 10; i = ++_i) { 
    todos = App.store.find(App.Todo, i); 
}