javascript - 从对象中删除未定义的值

Question

我在 javascript 中遇到问题，我想从对象中删除未定义的值

预期输出 数组中没有未定义值。

var result = [
  undefined,  
  undefined,
  {
    group: '1042000018356',
    email: '<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="9ce4e5e6dcf8f9eff7b2fff3f1" rel="noreferrer noopener nofollow">[email protected]</a>'
  },
  {
    group: '1042000098595',
    email: '<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="34555657745051475f1a575b59" rel="noreferrer noopener nofollow">[email protected]</a>'
  }
]

// This my logic:


result = result.map(function(index){

  for (var key in array) { // Looping
    if( index == key ){
      var group = array[key];  // Group id
      var email = key;         // Email
      return {group , email};
    }
  }
  
});
console.log("result", result);

如何从对象中删除未定义的值

谁能帮帮我吗？

Answer 1

您可以执行一个过滤器并传递一个 bool 构造函数，这将确保您从结果数组中删除所有 null 和未定义的值

var result  = [
  undefined,  
  undefined,
  {
    group: '1042000018356',
    email: '<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="9be3e2e1dbfffee8f0b5f8f4f6" rel="noreferrer noopener nofollow">[email protected]</a>'
  },
  {
    group: '1042000098595',
    email: '<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="88e9eaebc8ecedfbe3a6ebe7e5" rel="noreferrer noopener nofollow">[email protected]</a>'
  }
]

result = result.filter(Boolean);

console.log(result);