JSFiddle - React, Tailwind, and code Playground
by Lamik
JavaScript
var a = [{"x":"8/11/2009","y":0.026572007},{"x":"8/12/2009","y":0.025057454},{"x":"8/14/2009","y":0.031004457},{"x":"8/13/2009","y":0.024530916}]
var maxA = a.reduce((a,b)=>a.y>b.y?a:b).y; // 30 chars time complexity: O(n)
var maxB = a.sort((a,b)=>b.y-a.y)[0].y; // 27 chars time complexity: O(nlogn)
var maxC = Math.max(...a.map(o=>o.y)); // 26 chars time complexity: >O(2n)
document.body.innerHTML=`<pre>maxA: ${maxA}\nmaxB: ${maxB}\nmaxC: ${maxC}</pre>`;