als-statistics/lib/descriptive/mode.js

Modular JS statistics toolkit for Node.js and the browser: descriptive stats, correlations (Pearson/Spearman/Kendall), t-tests & ANOVA (Student/Welch), reliability (Cronbach’s alpha), regression (linear/logistic), clustering (DBSCAN/HDBSCAN), and table/co

function mode(values) {
   const freq = new Map();
   let maxFreq = 0;
   for (let num of values) {
      const count = (freq.get(num) || 0) + 1;
      freq.set(num, count);
      if (count > maxFreq) maxFreq = count;
   }

   const modes = [];
   for (const [val, count] of freq.entries()) {
      if (count === maxFreq) modes.push(val);
   }
   return modes.length === values.length ? [] : modes;
}

export default mode