直接上代碼

let str = 'apple';
let obj = {};
let number = 0;
let activeIndex = '';

[...str].map(key => {
    key in obj ? obj[key]++ : (obj[key] = 1);

    obj[key] > number ? (activeIndex = key) : '';
    number = obj[key];
});

console.log(activeIndex); // p

文章的內(nèi)容/靈感都從下方內(nèi)容中借鑒

• 【持續(xù)維護/更新 500+前端面試題/筆記】https://github.com/noxussj/Interview-Questions/issues

• 【大數(shù)據(jù)可視化圖表插件】https://www.npmjs.com/package/ns-echarts

• 【利用 THREE.JS 實現(xiàn) 3D 城市建模（珠海市）】https://3d.noxussj.top/