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This article mainly introduces the use of javascript associative array, which has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

Hash associative array definition

The code is as follows

/ / define an empty array

Myhash = {}

/ / define the array directly

Myhash = {"key1": "val1", "key2": "val2"}

/ / define arrays with Array

Myhash = new Array ()

Myhash ["key1"] = "val1"

Myhash ["key2"] = "val2"

Add key values to the Hash associative array

The code is as follows

/ / add a new key newkey with a key value of newval

Myhash ["newkey"] = "newval"

Delete existing key values of Hash associative array

The code is as follows

/ / Delete a key newkey, and at the same time, the newval corresponding to that key value disappears.

Delete myhash ["newkey"]

Traversing Hash associative arrays

The code copies the code as follows

/ / traverse the entire hash array

For (key in myhash) {

Val = myhash [key]

}

An example of easy use of Hash associative arrays

The code is as follows

Urlhash = {"yahoo": "www.111cn.net"

"baidu": "www.baidu.com"

"google": "www.google.cn"}

/ / Interactive usage example

Userinfo = prompt ("enter the search engine you most want to go to: (yahoo | baidu | google)", "yahoo")

[xss_clean] ("your choice:" + userinfo + "," + "to enter" + "" + userinfo + ".")

/ / getURL

/ / if the parameter is not defined, the www.111cn.net URL is returned by default

/ / @ param choice Select name

/ / @ return url actual URL

Function getURL (choice) {

Url = urlhash [choice]

If (typeof (urlhash [choice]) = = "undefined")

Url = "www.111cn.net"

Return url

}

/ / get all the keys of the hash list

/ / @ param hash hash array

/ / @ return keys key name data

Function array_keys (hash) {

Keys = []

For (key in hash)

Keys.push (key)

Return keys

}

For example:

/ / for the traversal of associative arrays, first define an array:

The code is as follows

Var arr = new Array ()

/ / the data for casually creating an associative array is as follows:

Arr ["name"] = "mary"

Arr ["age"] = "3"

Arr ["sex"] = "man"

/ / use the for loop to traverse as follows:

For (var keyin arr)

{

/ / then the value taken by the above key variable is "name" or "age" or "sex"

/ / instead of the value of the array

/ / the value below is the corresponding value.

Var value = arr [key]

}

The properties of objects in JS can be parenthesized "[]" or "." To visit, for example, a ["a"] and a.an above are equivalent.

Examples

The following code creates and initializes an associative array of three elements (note the format):

The code is as follows

Var MyArray = {"a": "Athens", "b": "Belgrade", "c": "Cairo"}

In this array, you can use a string ("a", "b", or "c") to address the element, rather than the number (0, 1, or 2) of the array element.

This allows you to create and use arrays with a more intuitive addressing scheme. You can also use the for shown above. In statement code to traverse the array.

For (key in myArray)

[xss_clean] ("Element value is" + MyArray [key] + "

);

For example:

Var myArray = {"a": "Athens", "b": "Belgrade", "c": "Cairo"}

For (key in myArray) {

[xss_clean] (key+ "=" + myArray [key] + "

")

}

[xss_clean] ("a =" + myArray ["a"])

Thank you for reading this article carefully. I hope the article "what are the uses of javascript associative arrays" shared by the editor will be helpful to you. At the same time, I also hope that you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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