Question

How to find keyword matching between multiple text blocks in JavaScript

Answer 1

/*
    Tokenize text into words.
    - Keeps only letters and digits
    - Splits on punctuation and spaces
*/
function tokenize(text) {
    const words = new Set();
    let word = "";
 
    for (const c of text) {
        if (/[A-Za-z0-9]/.test(c)) {
            word += c.toLowerCase();
        } else if (word.length > 0) {
            words.add(word);
            word = "";
        }
    }
 
    if (word.length > 0) {
        words.add(word);
    }
 
    return words;
}
 
/*
    // Find keyword matches across THREE OR MORE texts
    // -------------------------------------------------------------
    This function receives an array of sets.
    It returns the intersection of ALL sets.
*/
function findMatchesMultiple(allSets) {
    if (allSets.length === 0) return new Set();
 
    // Start with the first set
    let result = new Set(allSets[0]);
 
    // Intersect with each remaining set
    for (let i = 1; i < allSets.length; i++) {
        const temp = new Set();
 
        for (const w of result) {
            if (allSets[i].has(w)) {
                temp.add(w);
            }
        }
 
        result = temp;
    }
 
    return result;
}
 
// -------------------------------------------------------------
// Three text blocks to compare
// -------------------------------------------------------------
const text1 =
    "Machine learning allows computers to learn from data. " +
    "It is widely used in modern applications.";
 
const text2 =
    "Data science uses machine learning techniques. " +
    "Applications rely on data-driven models.";
 
const text3 =
    "Modern applications of machine learning include data analysis, " +
    "automation, and intelligent systems.";
 
// -------------------------------------------------------------
// Tokenize all texts
// -------------------------------------------------------------
const words1 = tokenize(text1);
const words2 = tokenize(text2);
const words3 = tokenize(text3);
 
// Put them into an array for multi-text comparison
const allSets = [words1, words2, words3];
 
// -------------------------------------------------------------
// Find keyword matches across ALL texts
// -------------------------------------------------------------
const matches = findMatchesMultiple(allSets);
 
// -------------------------------------------------------------
// Output results
// -------------------------------------------------------------
console.log("Matched Keywords Across ALL Texts:");
for (const w of matches) {
    console.log(w + " ");
}
 
 
/*
run:
 
Matched Keywords Across ALL Texts:
machine 
learning 
data 
applications 
 
*/

 

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