Efficiently finding a group of substrings within a JavaScript string

Question

Efficiently finding a group of substrings within a JavaScript string

I am currently working on a method to efficiently search for specific substrings within a given string. Here is my current implementation:

const apple = "apple"
const banana = "banana"
const chickoo = "chickoo"
const dates = "dates"
const eggplant = "eggplant"
const default = "default"

let string = "foobar" // This String changes dynamically
if (string.includes(apple)){
    return apple;
} else if (string.includes(banana)) {
    return banana;
} else if (string.includes(chickoo)) {
    return chickoo;
} else if (string.includes(dates)) {
    return dates;
} else if (string.includes(eggplant)) {
    return eggplant;
} else {
    return default;
}

While this approach is functional, I am seeking a more concise and effective way of conducting substring searches within a given string.

Edit: The updated version of my code looks like this:

const fruits = ["apple", "banana", "chickoo", "dates", "eggplant"];
let string = "foobar" //This is dynamic
for(let fruit in fruits) {
    if(string.includes(fruits[fruit])){
        return fruits[fruit];
    }
}
return "default";

If you have any suggestions for further improving the efficiency of this process, please let me know.

javascript typescript

Answer 1

Answer №1

Utilizing Regular Expressions:

function findFruitInString(input) {
    const match = input.match(/apple|banana|chickoo|dates|eggplant|default/);
    if(match)
        return match[0];
    return "default";
}

Important Information

This function will only retrieve the first fruit found in the string. For example, given the input "foobarapplebanana", it will return "apple". If you prefer to obtain an array of matching fruits like

[ "apple", "banana" ]

, then simply return match instead of match[0].

Test it out here

Answer 2

Utilizing Regular Expressions:

function findFruitInString(input) {
    const match = input.match(/apple|banana|chickoo|dates|eggplant|default/);
    if(match)
        return match[0];
    return "default";
}

Important Information

This function will only retrieve the first fruit found in the string. For example, given the input "foobarapplebanana", it will return "apple". If you prefer to obtain an array of matching fruits like

[ "apple", "banana" ]

, then simply return match instead of match[0].

Test it out here

Answer 3

Answer №2

You can quickly verify these includes in a single line of code.

Start by setting up the list of available items, then proceed to check if the desired item is present. If not found, the default value will be returned.

const apple = "apple"
const banana = "banana"
const cherry = "cherry"
const dates = "dates"
const eggplant = "eggplant"
const defaultValue = "default"

let selectedFruit = "kiwi" // This value can change

const availableOptions = [apple, banana, cherry, dates, eggplant]

return availableOptions.includes(selectedFruit) ? selectedFruit : defaultValue;

Answer 4

You can quickly verify these includes in a single line of code.

Start by setting up the list of available items, then proceed to check if the desired item is present. If not found, the default value will be returned.

const apple = "apple"
const banana = "banana"
const cherry = "cherry"
const dates = "dates"
const eggplant = "eggplant"
const defaultValue = "default"

let selectedFruit = "kiwi" // This value can change

const availableOptions = [apple, banana, cherry, dates, eggplant]

return availableOptions.includes(selectedFruit) ? selectedFruit : defaultValue;

Answer 5

Answer №3

If you're looking to filter an array based on a specific string, try utilizing the filter() method.

let searchString = "foobar" //This value can change
var matchingItems = items.filter(item => searchString.includes(item))
return matchingItems.length > 0 ? matchingItems[0] : "default"

Answer 6

If you're looking to filter an array based on a specific string, try utilizing the filter() method.

let searchString = "foobar" //This value can change
var matchingItems = items.filter(item => searchString.includes(item))
return matchingItems.length > 0 ? matchingItems[0] : "default"

Answer 7

Answer №4

A Straightforward Scenario

In situations where you only possess a few words, crafting a regular expression can be your solution - opt for either using match (refer to the accepted answer), or for simplicity's sake, simply extract the single word from the string:

found = string.replace(/.*(apple|banana|cherry).*/,"$1")

Do bear in mind that this will identify the last occurrence of the word. While string.match() is usually preferable, I aim to respect @maksymiuk's approach. The efficiency advantage with regex lies in its ability to scan the string just once, seeking out all potential matches.

However, if we delve into optimization, let's dive into another scenario:

Hunting Down Multiple Words

In instances involving numerous search terms (such as an entire vocabulary) against a relatively brief text, a different strategy may prove more effective. Create a roster of available words and cross-reference them with an object containing the dictionary's entries as keys.

function searchManyWordsInText(text,wordList) {
    let wordLookup = {};
    for(let w of wordList) wordLookup[w] = 1;
    let textWords = text.split(/\s+/);
    for(let x of textWords) if(wordLookup[x]) return x;
    return false;
}

//  test it:

searchManyWordsInText(
    'this is a banana championship',
    ['apple','banana','cherry']
);

//  returns 'banana', being the first encountered word

Answer 8

A Straightforward Scenario

In situations where you only possess a few words, crafting a regular expression can be your solution - opt for either using match (refer to the accepted answer), or for simplicity's sake, simply extract the single word from the string:

found = string.replace(/.*(apple|banana|cherry).*/,"$1")

Do bear in mind that this will identify the last occurrence of the word. While string.match() is usually preferable, I aim to respect @maksymiuk's approach. The efficiency advantage with regex lies in its ability to scan the string just once, seeking out all potential matches.

However, if we delve into optimization, let's dive into another scenario:

Hunting Down Multiple Words

In instances involving numerous search terms (such as an entire vocabulary) against a relatively brief text, a different strategy may prove more effective. Create a roster of available words and cross-reference them with an object containing the dictionary's entries as keys.

function searchManyWordsInText(text,wordList) {
    let wordLookup = {};
    for(let w of wordList) wordLookup[w] = 1;
    let textWords = text.split(/\s+/);
    for(let x of textWords) if(wordLookup[x]) return x;
    return false;
}

//  test it:

searchManyWordsInText(
    'this is a banana championship',
    ['apple','banana','cherry']
);

//  returns 'banana', being the first encountered word

Efficiently finding a group of substrings within a JavaScript string

Answer №1

Important Information

Answer №2

Answer №3

Answer №4

A Straightforward Scenario

Hunting Down Multiple Words

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