JavaScript条件语句实现按年龄与国家输出对应提示的问题求助

现有代码的错误点 #

• 年龄边界不符合要求：要求的「未满18」是<18、「未满21」是<21，你用了<=会把18、21岁的场景错分到错误分支
• 国家判断逻辑错误：不需要额外定义otherCountry变量，直接判断country变量是否等于'USA'即可，当前你写的&& country和&& otherCountry只是判断变量是否存在，永远为真，永远只会走到第一个匹配的分支
• 输出字符串拼写、内容和要求不一致，存在漏字、错字问题
• 包含多余的测试打印语句

修正后可直接运行的代码 #

const age = 20
const country = 'USA'

if (age < 16) {
  console.log("You're not old enough to do anything yet.")
} else if (age >= 16 && age < 18) {
  console.log("Be careful driving.")
} else if (age >= 18 && age < 21 && country === 'USA') {
  console.log("Go Vote!")
} else if (age >= 18 && age < 21 && country !== 'USA') {
  console.log("You can probably have some wine.")
} else {
  console.log("You're old enough to figure it out for yourself.")
}

优化建议 #

如果想减少重复的年龄判断，也可以把国家判断嵌套在18-21岁的分支内，代码更简洁：

const age = 20
const country = 'USA'

if (age < 16) {
  console.log("You're not old enough to do anything yet.")
} else if (age >= 16 && age < 18) {
  console.log("Be careful driving.")
} else if (age >= 18 && age < 21) {
  country === 'USA' ? console.log("Go Vote!") : console.log("You can probably have some wine.")
} else {
  console.log("You're old enough to figure it out for yourself.")
}

内容的提问来源于stack exchange，提问作者Rothhelm