A brief discussion on Javascript arrays and dictionaries

This article mainly briefly introduces Javascript arrays and dictionaries. Friends in need can refer to it.

Javascript’s array Array is both an array and a dictionary.

Let’s take an example to see how to use arrays.

var a = new Array();  
a[0] = "Acer";  
a[1] = "Dell";  
for (var i in a) {  
    alert(i);  
}

The above code creates an array, each element is a string object.

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

This is very similar to the properties of traversing objects mentioned in the previous article.

Let’s take a look at how to use the dictionary.

var computer_price = new Array();  
computer_price["Acer"] = 500;  
computer_price["Dell"] = 600;  
alert(computer_price["Acer"]);

We can even traverse this array (dictionary) as above

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

where i is each key value of the dictionary. The output result is:

Acer: 500
Dell: 600

Next, let’s take a look at the interesting part of Javascript, still the above example.

We can think of computer_price as a dictionary object, and each key value is an attribute.

That is to say, Acer is an attribute of computer_price. We can use it like this: computer_price.Acer

Let’s take a look at the simplified declaration method of dictionaries and arrays.

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

This declaration of the dictionary is the same as the previous one. In our example, Acer is a key value and can also be used as an attribute of the dictionary object.

The above is the entire content of this article. I hope you all like it. For more related tutorials, please visit JavaScript Video Tutorial!