有没有大大救我啊！！！

Question

统计句子 Whatever is worth doing is worth doing well 中字母e和字母o出现的次数

Answer 1

var arr = 'Whatever is worth doing is worth doing well';
var obj = {};
for (var i = 0; i < arr.length; i++) {
    var key = arr[i];
    if (obj[key]) {
        obj[key]++;
    } else {
        obj[key] = 1;
    }
}
console.log(obj['e'], obj['o']);

望采纳 

运行结果：