Generate new variables by utilizing an array

Question

Generate new variables by utilizing an array

Here is my array along with a loop that retrieves the keys (https://jsfiddle.net/ytm04L53/)

var i;
var feeds = ["test_user_201508_20150826080829.txt:12345","test_user_list20150826:666","test_list_Summary20150826.txt:321"];

for (i = 0; i < feeds.length; i++) {
    var feed = feeds[i];
    alert(feed.match(/\d+$/));
}

https://i.sstatic.net/F4kB9.jpg

The length of the array may vary, and I want to either use these keys as variables and assign their corresponding values after the : colon, or create new variables and assign the values from these keys to them.

How can I accomplish this in order to perform comparisons such as:

if (test_user > 5000) {dosomething}

update Thank you for the responses. How can I also create a set of variables and assign the array values to them? For example, like the following:

valCount(feeds.split(","));

function valCount(t) {
 if(t[0].match(/test_user_.*/))
  var testUser = t[0].match(/\d+$/);
 }

Sometimes there may be only one key in the array, other times two or three, so t[0] will not always be test_user_

I need to pass the array to a function and check for matches. If a key starts with test_user_, then retrieve the value and assign it to a specific variable.

Thanks everyone for your assistance!

javascript arrays

Answer 1

Answer №1

It is not feasible to generate dynamic variable names at runtime, although it is technically achievable.

Instead, you can opt for creating object properties:

var feeds = ["test_user_201508_20150826080829.txt:12345","test_user_list20150826:666","test_list_Summary20150826.txt:321"];

var obj = {};
feeds.forEach(function(entry) {
    var parts = entry.split(":"); // Splits the string on the :
    obj[parts[0]] = parts[1];     // Establishes the property
});

Through this approach,

obj["test_user_201508_20150826080829.txt"]

now holds the value "12345".

Interactive Example:

var feeds = ["test_user_201508_20150826080829.txt:12345","test_user_list20150826:666","test_list_Summary20150826.txt:321"];

var obj = {};
feeds.forEach(function(entry) {
    var parts = entry.split(":");
    obj[parts[0]] = parts[1];
});
snippet.log(obj["test_user_201508_20150826080829.txt"]);

<!-- This script introduces the `snippet` object, see http://meta.stackexchange.com/a/242144/134069 -->
<script src="http://tjcrowder.github.io/simple-snippets-console/snippet.js"></script>

Answer 2

It is not feasible to generate dynamic variable names at runtime, although it is technically achievable.

Instead, you can opt for creating object properties:

var feeds = ["test_user_201508_20150826080829.txt:12345","test_user_list20150826:666","test_list_Summary20150826.txt:321"];

var obj = {};
feeds.forEach(function(entry) {
    var parts = entry.split(":"); // Splits the string on the :
    obj[parts[0]] = parts[1];     // Establishes the property
});

Through this approach,

obj["test_user_201508_20150826080829.txt"]

now holds the value "12345".

Interactive Example:

var feeds = ["test_user_201508_20150826080829.txt:12345","test_user_list20150826:666","test_list_Summary20150826.txt:321"];

var obj = {};
feeds.forEach(function(entry) {
    var parts = entry.split(":");
    obj[parts[0]] = parts[1];
});
snippet.log(obj["test_user_201508_20150826080829.txt"]);

<!-- This script introduces the `snippet` object, see http://meta.stackexchange.com/a/242144/134069 -->
<script src="http://tjcrowder.github.io/simple-snippets-console/snippet.js"></script>

Answer 3

Answer №2

Follow this example to achieve the desired result by utilizing the split method:

let index;
let items = ["example_item_20201012:54321", "sample_item_list20201012:987", "list_summary20201012.txt:654"];

for (index = 0; index < items.length; index++) {
    let item = items[index];
    console.log(item.split(/[:]/));
}

The above code will produce the following output:

["example_item_20201012", "54321"]
["sample_item_list20201012", "987"]
["list_summary20201012.txt", "654"]

Answer 4

Follow this example to achieve the desired result by utilizing the split method:

let index;
let items = ["example_item_20201012:54321", "sample_item_list20201012:987", "list_summary20201012.txt:654"];

for (index = 0; index < items.length; index++) {
    let item = items[index];
    console.log(item.split(/[:]/));
}

The above code will produce the following output:

["example_item_20201012", "54321"]
["sample_item_list20201012", "987"]
["list_summary20201012.txt", "654"]

Answer 5

Answer №3

To extract relevant information, utilize the split method

var feeds = ["test_user_201508_20150826080829.txt:12345","test_user_list20150826:666","test_list_Summary20150826.txt:321"];

feedMap = {}
for (i = 0; i < feeds.length; i++) {
    var temp = feeds[i].split(':');
    feedMap[temp[0]] = temp[1];
}

The result will be:

{
    "test_user_201508_20150826080829.txt":"12345",
    "test_user_list20150826":"666",
    "test_list_Summary20150826.txt":"321"
}

You can access the data using the following structure:

feedMap["test_user_201508_20150826080829.txt"]

For further reference, check out this codepen link

Answer 6

To extract relevant information, utilize the split method

var feeds = ["test_user_201508_20150826080829.txt:12345","test_user_list20150826:666","test_list_Summary20150826.txt:321"];

feedMap = {}
for (i = 0; i < feeds.length; i++) {
    var temp = feeds[i].split(':');
    feedMap[temp[0]] = temp[1];
}

The result will be:

{
    "test_user_201508_20150826080829.txt":"12345",
    "test_user_list20150826":"666",
    "test_list_Summary20150826.txt":"321"
}

You can access the data using the following structure:

feedMap["test_user_201508_20150826080829.txt"]

For further reference, check out this codepen link

Answer 7

Answer №4

If you're in a pinch and absolutely must generate variables dynamically, here's a workaround code snippet:

for (i = 0; i < feeds.length; i++) 
{
    var feed = feeds[i];
    window[feed.substring(0, feed.indexOf(":"))] = feed.match(/\d+$/);
}

alert(test_user_201508_20150826080829)

Do keep in mind that variable names cannot contain certain special characters such as '.'

Best, Michał

Answer 8

If you're in a pinch and absolutely must generate variables dynamically, here's a workaround code snippet:

for (i = 0; i < feeds.length; i++) 
{
    var feed = feeds[i];
    window[feed.substring(0, feed.indexOf(":"))] = feed.match(/\d+$/);
}

alert(test_user_201508_20150826080829)

Do keep in mind that variable names cannot contain certain special characters such as '.'

Best, Michał

Generate new variables by utilizing an array

Answer №1

Answer №2

Answer №3

Answer №4

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