js for 获取对象属性

var arr = ['a', 'b', 'c'];
// 1
for (var index = 0; index < arr.length; index++)
{
	console.log(arr[index]);
}

// 2 ES5
arr.forEach(function (value) {
	console.log(value);
});

// 3  for-in work the array or string or other collections that will return an index  
for (var index in arr)
{
        console.log(arr[index]);
}

// 4 ES6
for (var value of arr)
{
	console.log(value);
}



// the for-of also works on strings,set, map
var str = "hello boy";
for (var s of str)
{
	console.log(s);
}

var words = ['just', 'do', 'it', 'it'];
var uniqueWords = new Set(words);
// console.log(uniqueWords);
for (var word of uniqueWords)
{
	console.log(word);
}


var MyMap = new Map();

for (var index in Map)
{
	  
}