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How to check presence of a URL parameter compared to an Array?

Given these two sample urls and code. How can I use the Array as a reference to check if the values are in the UTM parameter? (There will ONLY be one utm parameter at any given time).
example.com?utm=test
example.com?utm=test2
var partnerArray = ["test", 'test2'];
function findPartner() {
if window.location.href.indexOf('?utm='(partnerArray)' !== -1) {
//do something fun here
}
I know my code is wrong - I haven't found example of using an Array to check for values in the URL.
Thank you.

Let's split this into two problems. First, getting the value of the utm parameter:
function getUTM() {
return new URLSearchParams(window.location.search).get("utm");
}
Then, figuring out whether it's one of the known partners, and returning the one it might be.
const partnerArray = ["test", 'test2'];
function getPartner() {
const utm = getUTM();
return partnerArray.find(partner => partner === utm);
}
getPartner() will return undefined if the query string's utm parameter doesn't match either known partner.

Thanks all those that gave input. Here's my solution for future readers with parts from the comments.
1st: Establish an Array:
var partnerArray1 = ["test1", 'test2'];
var partnerArray2 = ["test3", 'test4'];
2nd: Check what is in the URL's UTM parameter value
var urlParams = new URLSearchParams(window.location.search).get("utm");
3rd: Make a function to check the value against the Array:
function checkUTM() {
if (partnerArray1.indexOf(urlParams) !== -1){
//do some cool stuff here
}
if (partnerArray2.indexOf(urlParams) !== -1){
//do some more cool stuff here
}
}
Short of figuring out how to pass values into the function and check that, I went with the slightly more messy way, but it accomplished my goal. If there are improvements to the above, please feel free to provide clear updated samples.

How to make indexOf only match 'hi' as a match and not 'hirandomstuffhere'?

Basically I was playing around with an Steam bot for some time ago, and made it auto-reply when you said things in an array, I.E an 'hello-triggers' array, which would contain things like "hi", "hello" and such. I made so whenever it received an message, it would check for matches using indexOf() and everything worked fine, until I noticed it would notice 'hiasodkaso', or like, 'hidemyass' as an "hi" trigger.
So it would match anything that contained the word even if it was in the middle of a word.
How would I go about making indexOf only notice it if it's the exact word, and not something else in the same word?
I do not have the script that I use but I will make an example that is pretty much like it:
var hiTriggers = ['hi', 'hello', 'yo'];
// here goes the receiving message function and what not, then:
for(var i = 0; i < hiTriggers.length; i++) {
if(message.indexOf(hiTriggers[i]) >= 0) {
bot.sendMessage(SteamID, randomHelloMsg[Math stuff here blabla]); // randomHelloMsg is already defined
}
}
Regex wouldn't be used for this, right? As it is to be used for expressions or whatever. (my English isn't awesome, ikr)
Thanks in advance. If I wasn't clear enough on something, please let me know and I'll edit/formulate it in another way! :)

You can extend prototype:
String.prototype.regexIndexOf = function(regex, startpos) {
var indexOf = this.substring(startpos || 0).search(regex);
return (indexOf >= 0) ? (indexOf + (startpos || 0)) : indexOf;
}
and do:
var foo = "hia hi hello";
foo.regexIndexOf(/hi\b/);
Or if you don't want to extend the string object:
foo.substr(i).search(/hi\b/);
both examples where taken from the top answers of Is there a version of JavaScript's String.indexOf() that allows for regular expressions?

Regex wouldn't be used for this, right? As it is to be used for expressions or whatever. (my > English isn't awesome, ikr)
Actually, regex is for any old pattern matching. It's absolutely useful for this.
fmsf's answer should work for what you're trying to do, however, in general extending native objects prototypes is frowned upon afik. You can easily break libraries by doing so. I'd avoid it when possible. In this case you could use his regexIndexOf function by itself or in concert with something like:
//takes a word and searches for it using regexIndexOf
function regexIndexWord(word){
return regexIndexOf("/"+word+"\b/");
}
Which would let you search based on your array of words without having to add the special symbols to each one.

Matching Array to JavaScript Matrix

I’m wondering how to solve a matching/lookup problem and I “think” a multi-dimensional array is the solution. In short, I want to match a list of comma separated SKUs stored as a cookie value against a finite list of SKUs with matching product names and print out the matched product names onto the page. I’m not sure if this is the best way to do this, but with what I have so far I’m not clear how to properly breakup the comma separated strings from the cookie (right now it’s trying to match the entire cookie value), match them to the matrix (17 total rows) and then print out the Product Name.
<script>
var staticList = [
[“1234”, “Chocolate Ice Cream”],
[“1235”, “Peanut Butter Cookie”],
[“6G2Y”, “Raspberry Jell-O”],
[“YY23”, “Vanilla Wafers”]
];
var cookieSkus = [‘1235,YY23’]; // comma separated value from cookie
jQuery(function () {
for (var i = 0; i < staticList.length; i++) {
if (cookieSkus.indexOf(staticList [i][0]) > -1) {
jQuery('#pdisplay).append(staticList [i] [1] + '<br />');
}
}
});
</script>
<p id=”pdisplay”></p>
In this example, the paragraph "pdisplay" would contain:
Peanut Butter Cookie
Vanilla Wafers
Is there a way to correct what I have above or is there a better method of accomplishing what I’m trying to do?

First, you might want to focus on the Cookie SKUs rather than the staticList. The reason for this is that the cookie may have a variable number, and may be as small as 0 elements. (After all, we don't need to list the items if there are no items).
This may be accomplished simply by converting the string to an array and then checking if the SKU is in the staticList. Unfortunately, since you are using a multidimensional array, this would require going through the staticList for each cookie sku. Using just this suggestion, here is a basic example and fiddle:
Rewrite: Accounting for the fact that staticList is an Array of Arrays
jQuery(function() {
var skus = cookieSkus[0].split(',');
for (var i = 0; i < skus.length; i++) {
for (var j = 0; j < staticList.length; j++) {
if (staticList[j][0] == skus[i]) {
jQuery('#pdisplay').append(staticList[j][2] + '<br/>');
break; // Will end inner if the item is found... Saves a lot of extra time.
}
}
}
});
Edit 2: Using an Object (A possibly better approach)
According to the comments, you must support IE8. In this case, you might consider an Object instead of a multi-dimensional array. The reasons for this are as follows:
An object is actually an associative array (with a few perks).
You can directly check for property existence without having any nested arrays.
Object property access is typically faster than looping through an array
You can access object properties nearly exactly like accessing an array's elements.
When using an Object, the original version of my code may be used without modification. This is because the object's structure is simpler. Here is a fiddle for you: option 2
var staticList = {
"1234": "Chocolate Ice Cream",
"1235": "Peanut Butter Cookie",
"6G2Y": "Raspberry Jell-O",
"YY23": "Vanilla Wafers"
};
jQuery(function() {
var skus = cookieSkus[0].split(',');
for (var i = 0; i < skus.length; i++) {
if (staticList[skus[i]])
jQuery('#pdisplay').append(staticList[skus[i]] + '<br/>');
}
});
Responding to your comment:
The reason that the output matches what is desired is because unlike an array which has numerical indices, the object's indices are the actual skus. So, there is no staticList[0] if staticList is an object. Instead (in the context of the staticList object), 1234 = "Chocolate Ice Cream". So, an object definition basically goes as follows:
var objectName = {
index1: value1,
index2: value2,
...,
...
}
The index may be any primitive value (integer or string). The value may be any valid javascript value including a function or an inner object. Now, to get the value at a specific index, you may do either:
objectName.index1 (no quotes)
OR:
objectName["index1"] (quotes needed if the index is a string)
The result of either of those will be:
value1
It's as simple as that.

I would try something like this:
var cookieSkus = cookieSkus[0].split(',');
staticList.filter(function(cell){
return cookieSkus.some(function(val){return cell[0] === val; });
}).map(function(cell){
jQuery('#pdisplay).append(cell[1] + '<br />');
});
Disclaimer: provided based on the sample code provided above along with recent comments

javascript validate value against array

I'm looking for a way to verify against an array.
I'm lost in the array searching part.
I may get an array like this:
stream = ["apple","orange", "grape", "peach","strawberry","watermelon", "kiwi", "raspberry"];
But I only want :
selection = ["apple", "peach","strawberry","kiwi", "raspberry"];
How would I write a statement that would say:
If something in this stream matches my selection, do something.

You must use the inArray command like this:
if($.inArray(ValueToCheck, YourArray) > -1) { alert("Value exists"); }
InArray will search your array for the value you asked for and return its index. If the value isn't present, it returns -1.

var stream = ["apple","orange", "grape", "peach","strawberry","watermelon", "kiwi", "raspberry"],
selection = ["apple", "peach","strawberry","kiwi", "raspberry"];
stream.forEach(function(elem) {
if( selection.indexOf(elem) > -1 ) {
// we have a match, do something.
}
});
Note that Array.prototype.forEachhelp and .indexOf()help are part of Javascript 1.6 and may not be supported by any InternetExplorer < version 9. See MDC's documentation on alternative versions.
There are lots of other ways to accomplish the same thing (using a "normal" for-loop for instance) but I figured this is probably the best trade-of in performans vs. readability.
Anyway, all the used Javascript 1.6 functions are actually very trivial to write on your own.
jQuerys $.inArray()help will also use Array.prototype.indexOf() if it's supported by the browser.

fastest way to detect if a value is in a group of values in Javascript

I have a group of strings in Javascript and I need to write a function that detects if another specific string belongs to this group or not.
What is the fastest way to achieve this? Is it alright to put the group of values into an array, and then write a function that searches through the array?
I think if I keep the values sorted and do a binary search, it should work fast enough. Or is there some other smart way of doing this, which can work faster?

Use a hash table, and do this:
// Initialise the set
mySet = {};
// Add to the set
mySet["some string value"] = true;
...
// Test if a value is in the set:
if (testValue in mySet) {
alert(testValue + " is in the set");
} else {
alert(testValue + " is not in the set");
}

You can use an object like so:
// prepare a mock-up object
setOfValues = {};
for (var i = 0; i < 100; i++)
setOfValues["example value " + i] = true;
// check for existence
if (setOfValues["example value 99"]); // true
if (setOfValues["example value 101"]); // undefined, essentially: false
This takes advantage of the fact that objects are implemented as associative arrays. How fast that is depends on your data and the JavaScript engine implementation, but you can do some performance testing easily to compare against other variants of doing it.
If a value can occur more than once in your set and the "how often" is important to you, you can also use an incrementing number in place of the boolean I used for my example.

A comment to the above mentioned hash solutions.
Actually the {} creates an object (also mentioned above) which can lead to some side-effects.
One of them is that your "hash" is already pre-populated with the default object methods.
So "toString" in setOfValues will be true (at least in Firefox).
You can prepend another character e.g. "." to your strings to work around this problem or use the Hash object provided by the "prototype" library.

Stumbled across this and realized the answers are out of date. In this day and age, you should not be implementing sets using hashtables except in corner cases. You should use sets.
For example:
> let set = new Set();
> set.add('red')
> set.has('red')
true
> set.delete('red')
true
> set.has('red')
false
Refer to this SO post for more examples and discussion: Ways to create a Set in JavaScript?

A possible way, particularly efficient if the set is immutable, but is still usable with a variable set:
var haystack = "monday tuesday wednesday thursday friday saturday sunday";
var needle = "Friday";
if (haystack.indexOf(needle.toLowerCase()) >= 0) alert("Found!");
Of course, you might need to change the separator depending on the strings you have to put there...
A more robust variant can include bounds to ensure neither "day wed" nor "day" can match positively:
var haystack = "!monday!tuesday!wednesday!thursday!friday!saturday!sunday!";
var needle = "Friday";
if (haystack.indexOf('!' + needle.toLowerCase() + '!') >= 0) alert("Found!");
Might be not needed if the input is sure (eg. out of database, etc.).
I used that in a Greasemonkey script, with the advantage of using the haystack directly out of GM's storage.

Using a hash table might be a quicker option.
Whatever option you go for its definitely worth testing out its performance against the alternatives you consider.

Depends on how much values there are.
If there are a few values (less than 10 to 50), searching through the array may be ok. A hash table might be overkill.
If you have lots of values, a hash table is the best option. It requires less work than sorting the values and doing a binary search.

I know it is an old post. But to detect if a value is in a set of values we can manipulate through array indexOf() which searches and detects the present of the value
var myString="this is my large string set";
var myStr=myString.split(' ');
console.log('myStr contains "my" = '+ (myStr.indexOf('my')>=0));
console.log('myStr contains "your" = '+ (myStr.indexOf('your')>=0));
console.log('integer example : [1, 2, 5, 3] contains 5 = '+ ([1, 2, 5, 3].indexOf(5)>=0));

You can use ES6 includes.
var string = "The quick brown fox jumps over the lazy dog.",
substring = "lazy dog";
console.log(string.includes(substring));