I currently have a string and set of substrings/search strings which I want to effectively search in the given string. This is what I have currently:

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;
}

This approach works, however I am looking for a more compact and efficent way of searching for substrings in a given string.

Edit: I am currently using the following way:

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";

Let me know if there is even more effective way to do this than the above one.

CodePudding user response：

Using Regex:

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

Note

this will only return the first matching fruit in the string. So "foobarapplebanana" will return "apple". If instead you want to return an array of strings, [ "apple", "banana" ], then return match instead of match[0].

Test Here

CodePudding user response：

You can check these includes in one line.

First you have to create the available list and then check it. If it was not found in the list, default is returned.

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

const availableFruits = [apple, banana, chickoo, dates, egplant]

return availableFruits.includes(string) ? string : default;

CodePudding user response：

You can use filter()

let string = "foobar" //This is dynamic
var matchingFruits =  fruits.filter(fruit=>string.includes(fruit))
return matchingFruit.length>0?matchingFruit[0]:"default"

CodePudding user response：

It depends.

Regex could give you a simple answer:

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

But if there are many search strings (like a whole dictionary) and you only have a relatively short text, a reverse approach could be more efficient: build a list of words you have, and check them against an object that has the dictionary words as keys.