的CoffeeScript - 数组初始化

Question

我有以下的代码，明显的作品，但我相当肯定存在的CoffeeScript表达这种更简洁的方式：

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]) 

的圆括号表示list comprehension，这将返回值收集到数组中并返回。

考虑下面的两个例子。封闭的圆括号改变了Coffeescript解释循环的方式。

# 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] 

和输出：

// 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); 
}