---
# System prepended metadata

title: javascript object 物件
tags: [object, javascript]

---

# javascript object 物件
###### tags: `javascript` `object`
### Login input information (creating object)
```javascript=
var jsbook = {title:'Javascript starter book',price: 500, stock: 3}
		console.log(jsbook)
```


### Reading the information inside the object
```javascript=
var jsbook = {title:'Javascript starter book',price: 500, stock: 3}
		console.log(jsbook.price)
		console.log(jsbook['price'])
		jsbook.stock= 10;
		console.log(jsbook.stock)
```

### read all type(class)   (for.. in ..)
```javascript=
var jsbook = {title:'Javascript starter book',price: 500, stock: 3}
		
		for(var p in jsbook) {
			console.log(p + '='+ jsbook[p]);
		}
```

### input to html
```htmlmixed=
<!DOCTYPE html> <!-- 物件(object) 檔名請設為: ObjectTest.html -->
<html>
<head>
<section> <!-- 將所有項目輸出至HTML -->
<table>
<tr>
<td id="title"></td>
<td id="price"></td>
<td id="stock"></td>
</tr>
</table>
</section>
</head>
<body>
<script>
var jsbook = {title:'javascript 入門書', price: 500, stock: 3}

document.getElementById('title').textContent = jsbook.title;
document.getElementById('price').textContent = jsbook.price+'元';
document.getElementById('stock').textContent = jsbook.stock;
</script>
</body>
</html>
```

## Show a readable date formatre - [Date 物件]

```htmlmixed=
var now = new Date();
var year = now.getFullYear();
var month = now.getMonth();
var date = now.getDate();
var hour = now.getHours();
var min = now.getMinutes();
var sec = now.getSeconds();

var ampm = ' ';
if(hour < 12){
  ampm = 'a.m.'
}else{
  ampm = 'p.m.'
}


var output = year+"/"+(month+1)+"/"+date+"_"+(hour%12)+":"+min+":"+ampm;
document.getElementById('time').textContent = output
```

### There is still some object that don't need to do a startup setting
1. Math.random();
2. windows.alert();
3. document.getElementById();

How to know?
1. Can make alot of obeject at the start



<!DOCTYPE html>
<html>
	<head>
	
	</head>
	
	<body>
		<script>
			var addZero = function(num, digit){
				var numString = String(num) ;
				while(numString.length < digit){
					numString = '0' + numString
				}
				 return numString;
			}
			//console.log(addZero(1,2)) //Please put the 1 two the tenth decimal
			var songs = [
				'Starlight',
				'Doll',
				'Car',
				'Be a song',
				'My Favorite Things',
				'Taking A Chance On Love',
				'Fly Me To The Moon',
				'Waltz For Debby',
				'Willow Weep For Me',
				'Bluesette'
			];
			for(var i - 0; i < song.length; i++){
				var paragraph = documentElement('p')
				paragraph.textContent = addZero(i + 1,2) +'. '+song[i];
			}
		</script>
        <dy>
        <ml>
	</body>
</html>