Detailed explanation of the relationship between Array and Object in Javascript

In

Javascript,Arrayis alsoObject, but some people may mistakenly believe that access in the form a['key'] is Array. Function, actually not.

In the following example, after Array is assigned a value, its length property is still 0, because the data is not placed in the array position, but is placed in the Array's prototype object Object.

var a = new Array(); a['one'] = 1; a['two'] = 2; a['three'] = 3; alert(a.length);

Another important point:

When javascript instantiates an object, you can create the object in the form {key:value}. The key can be a direct quantity or astring. In the following example, the contents of a1 and a2 are exactly the same.

It should be noted that var1 of a1 or a2 will not be replaced with 'pm'.

var var1 = 'pm'; var a1 = {var1:'test is ok',var2:'here'}; alert(a1.var1);

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