字符串中字母的出现次数

[Sunny Fu]

字符串中字母的出现次数

[Guotong Liao]

const str = "ABCabc123"
let res = 0
for (const c of str)
    if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
        res++
console.log(res)  // 6

[beary]

function count(str){
    let res = 0;
    for(let i = 0; i < str.length; i++){
        if(str[i] >= 'a' && str[i] <= 'z' || (str[i] >= 'A' && str[i] <= 'Z')) res++;
    }
    return res;
}
console.log(count("ABCabc123"));

如果是要统计每个字母的次数，可以用map

[fencer]

const reg = /[^a-zA-Z]/g;
const str = "ABCabc123";
console.log(str.replaceAll(reg, '').length)

[Banks1y]

const str = "ABCabc123";
let res = str.split("").reduce((pre, cur) => {
  if (!pre[cur]) pre[cur] = 1;
  else pre[cur]++;
  return pre;
}, {});
console.log(res);