如果您在JavaScript中廢棄了用過的對象，您是否保存了可能的傻垃圾集合？

Question

如果你在JavaScript中廢棄了用過的對象，你是否保存了可能的愚蠢的垃圾收集？

例如。

如果通過在JavaScript中一些用戶重複：

var users = [ 
    { FirstName: "Chris", LastName: "Pearson" }, 
    { FirstName: "Kate", LastName: "Johnson" }, 
    { FirstName: "Josh", LastName: "Sutherland" }, 
    { FirstName: "John", LastName: "Ronald" }, 
    { FirstName: "Steve", LastName: "Pinkerton" } 
]; 

// Do something with the data, perhaps put it in a table 

users = null; 

是現在值得抵消該名單？有沒有人有一些科學背後的性能提升，或者如果這是浪費時間等？

有時很難向人們解釋爲什麼你以某種方式做某件事，我知道它在很多場合保存了我的培根，當然，C++，但是在JavaScript中，是否有任何實驗來確定它是否值得在JavaScript？找到我可以信任的sizeof函數，讓我哭泣......如果有人已經做過這種實驗，我會非常感謝你看到你的想法！

Answer 1

這取決於具體情況。例如，在這裏它是無用的：

function putUsersInTable(){ 
    var users = [ 
     { FirstName: "Chris", LastName: "Pearson" }, 
     { FirstName: "Kate", LastName: "Johnson" }, 
     { FirstName: "Josh", LastName: "Sutherland" }, 
     { FirstName: "John", LastName: "Ronald" }, 
     { FirstName: "Steve", LastName: "Pinkerton" } 
    ]; 

    // Do something with the data 

    users = null; // Useless, the data could be GC'd anyways 
} 

這將使得數據不被GC'd時，不能以其他方式：

function putUsersInTable(){ 
    var users = [ 
     { FirstName: "Chris", LastName: "Pearson" }, 
     { FirstName: "Kate", LastName: "Johnson" }, 
     { FirstName: "Josh", LastName: "Sutherland" }, 
     { FirstName: "John", LastName: "Ronald" }, 
     { FirstName: "Steve", LastName: "Pinkerton" } 
    ]; 

    // Do something with the data 

    // This could be an event hander in the DOM or any global variable 
    outsidethisscope = function(){ 
     // This anonymous function has access to users, 
     // But doesn't necessarily make use of it 
     console.log('Hi'); 
    } 

    users = null; // Removes the only reference to that array, 
        // allowing it to be GC'd 
}