Javascript arrays and dictionaries

Javascript array Array, is both an array, also a dictionary (Dictionary).

First example look at the usage of the array.

Javascript code  

1. var a = new Array();  
2. a[0] = "Acer";  
3. a[1] = "Dell";  
4. for (var i in a) {  
5.     alert(i);          
6. }  

The above code is the creation of an array, each element is a string object.

Then traverse the array. Note that the result is 0 and i is 1, a [i] The result was a string.

This is very like the one on the property traverse the object of it comes in.

 

Here's look at the use of the dictionary.

Javascript code  

1. var computer_price = new Array();  
2. computer_price["Acer"] = 500;  
3. computer_price["Dell"] = 600;  
4. alert(computer_price["Acer"]);  

We even like above can also traverse the array (dictionary)

Javascript code  

1. for (var i in computer_price) {  
2.     alert(i + ": " + computer_price[i]);  
3. }  

where i is the key for each dictionary. The output is:

Acer: 500

Dell: 600

 

Below, a look at the interesting thing about Javascript, or the above examples.

We can computer_price as a dictionary object, but it is a key value of each property.

That is a property computer_price of Acer. We can use it like this: computer_price.Acer

 

Next, look at ways to simplify the statement dictionaries and arrays.

Javascript code  

1. Array = var [. 1, 2,. 3];  // Array  
2. var array2 = { "Acer": 500, "Dell": 600 }; // 字典  
3. alert(array2.Acer); // 50  

Such statements and the dictionary is in front of the same. In our example, Acer is key, but also as an attribute of the object dictionary.

Reproduced in: https: //www.cnblogs.com/kungfupanda/p/4062657.html