Javascript變量定義 - 澄清

Question

下面的聲明是什麼意思？我知道lines = []是一個數組，但我不知道其他人。

實際的代碼是使用JavaScript XPCOM

var line = {}, lines = [], hasmore; 
do { 
     hasmore = istream.readLine(line); 
     lines.push(line.value); 
} while(hasmore); 

Answer 1

逐行讀取文件中的行它創建3個變量

var line = {}; // creates an object 
var lines = []; // creates an array 
var hasmore;  // undefined 

Answer 2

聲明3個變量（參見：Declaring Multiple Variables in JavaScript）。

var line = {} // creates an empty object literal 
    lines = [] // creates an empty array literal 
    hasmore // creates an empty undefined variable, which can hold any datatype 

Answer 3

來吧，試試這個控制檯上：

var line = {}, lines = [], hasmore; 

然後訪問它們，你會看到：

line is Object, 
lines is an array 
hasmore is undefined