我可以在 function arguments 中对 Strings 在 JS 中使用逻辑或运算符吗？ Function 不评估第二个字符串（我认为）

Question

I check the backend through Vuex to conditionally render error messages. I have the following function:

const getByTitle = (memberTitle) => {
  return state.errors.find(e => e.meta.memberTitle === memberTitle)
       ?.content.error.title;   
}

Now, as an argument I would like to pass 2 strings, as there are 2 options in this component.

getNumber() {
  return this.getErrorByMemberId('B2Bvr' || 'Cvr' || undefined);
},

If the correct value in the backend is Cvr , then in this case I unfortunately don't get the error message (because it comes after B2Bvr ). If I change the order of the arguments (see following snippet) abd put the correct value first ( Cvr ), then it works and correctly displays the error message.

getNumber() {
  return this.getErrorByMemberId('Cvr' || 'B2Bvr' || undefined);
},

Why does it stop in the first argument? And does not evaluate the second one? Which is the correct way to use Logical OR operators in parameters?

Answer 1

It stops at the first argument because that's the first argument that is truthy, so the other arguments are ignored. If you attempted to call the function with undefined first (falsy value), it would skip that one and send the second argument.

One way to accomplish your intended goal would be to send all possible arguments as an array of arguments and use Array.includes() in your function:

getNumber() {
  return this.getErrorByMemberId(['Cvr', 'B2Bvr', undefined]);
},

const getByTitle = (memberTitleArray) => {
  return state.errors.find(e => memberTitleArray.includes(e.meta.memberTitle))
       ?.content.error.title;   
}