Question

我的代码不起作用。我需要反馈，并且需要一种有效的方法来返回与传递给函数的ID匹配的名字和姓氏的缩写。

var contactList = [
    {
    "id": 'e3d46de8c7194cb1a32275195c15dc07',
    "name": 'Niels Bohr',
    "num_messages": 62,
    },
    {
    'id': '7064c3f9c99743b2838bbd8eacafe0d6',
    "name": 'Max Planck',
    "num_messages": 15,
    },
    {
    "id": 'b19e575a0d3f4151a1391452d8a47a44',
    "name": 'Jane Goodall',
    "num_messages": 20,
    },
    {
    "id": '17d9d0908f454253b5337e8c1ef4b564',
    "name": "Caroline Herschel",
    "num_messages": 3,
    },
]

function getInitials(id){
    // find the user object
    for (let u of contactList) {
        if (u["id"] == id){
            var initials = ''
            names = u.name.split(' ')
            for(var i; i < names.length; i++){
                initials += names[i][0]
            }
            // return the initials
            return initials
        }
    }
}

Answer 1

首先使用 find() 找到与id匹配id的商品。然后split()及其name并将其映射到其name[0]然后是join()

var contactList = [
    {
    "id": 'e3d46de8c7194cb1a32275195c15dc07',
    "name": 'Niels Bohr',
    "num_messages": 62,
    },
    {
    'id': '7064c3f9c99743b2838bbd8eacafe0d6',
    "name": 'Max Planck',
    "num_messages": 15,
    },
    {
    "id": 'b19e575a0d3f4151a1391452d8a47a44',
    "name": 'Jane Goodall',
    "num_messages": 20,
    },
    {
    "id": '17d9d0908f454253b5337e8c1ef4b564',
    "name": "Caroline Herschel",
    "num_messages": 3,
    },
]
function getInitials(id){
    let obj = contactList.find(item => item.id === id);
	return obj && obj.name.split(' ').map(a => a[0]).join('');
}
console.log(getInitials('7064c3f9c99743b2838bbd8eacafe0d6'))
console.log(getInitials('17d9d0908f454253b5337e8c1ef4b564'))
console.log(getInitials('b19e575a0d3f4151a1391452d8a47a44'))
console.log(getInitials('0'))

Answer 2

您可以找到对象，获取名称并创建其初始内容。

function getInitials(array, id) {
    var temp = array.find(o => o.id === id);
    return temp && temp.name.split(' ').map(([c]) => c).join('');
}

var contactList = [{ id: 'e3d46de8c7194cb1a32275195c15dc07', name: 'Niels Bohr', num_messages: 62 }, { id: '7064c3f9c99743b2838bbd8eacafe0d6', name: 'Max Planck', num_messages: 15 }, { id: 'b19e575a0d3f4151a1391452d8a47a44', name: 'Jane Goodall', num_messages: 20 }, { id: '17d9d0908f454253b5337e8c1ef4b564', name: "Caroline Herschel", num_messages: 3 }];

console.log(getInitials(contactList, 'b19e575a0d3f4151a1391452d8a47a44'));
console.log(getInitials(contactList, '000'));

Answer 3

您可以尝试以下代码

var contactList = [
    {
    "id": 'e3d46de8c7194cb1a32275195c15dc07',
    "name": 'Niels Bohr',
    "num_messages": 62,
    },
    {
    'id': '7064c3f9c99743b2838bbd8eacafe0d6',
    "name": 'Max Planck',
    "num_messages": 15,
    },
    {
    "id": 'b19e575a0d3f4151a1391452d8a47a44',
    "name": 'Jane Goodall',
    "num_messages": 20,
    },
    {
    "id": '17d9d0908f454253b5337e8c1ef4b564',
    "name": "Caroline Herschel",
    "num_messages": 3,
    },
]

//here constant is your id which you passed in if condition
var str = contactList.find(x => x.id =='17d9d0908f454253b5337e8c1ef4b564').name.split(' ');
var result =""
for(var s of str)
   result += s.substr(0, 1)
   
console.log("Initals of \""+str+"\" is " + result);

Answer 4

尝试一下，可能是您需要的吗？

var contactList = [
    {
    "id": 'e3d46de8c7194cb1a32275195c15dc07',
    "name": 'Niels Bohr',
    "num_messages": 62,
    },
    {
    'id': '7064c3f9c99743b2838bbd8eacafe0d6',
    "name": 'Max Planck',
    "num_messages": 15,
    },
    {
    "id": 'b19e575a0d3f4151a1391452d8a47a44',
    "name": 'Jane Goodall',
    "num_messages": 20,
    },
    {
    "id": '17d9d0908f454253b5337e8c1ef4b564',
    "name": "Caroline Herschel",
    "num_messages": 3,
    },
]

function getInitials(id){
    // find the user object
    for (let u of contactList) {
        if (u["id"] == id){
            var initials = ''
            names = u.name.split(' ')
            console.log(names.length);
            for(var i=0; i< names.length; i++){
            
              initials+=' ' + names[i].charAt(0);
            }
            // return the initials
            console.log(initials, 'pop');
            return initials
        }
    }
}
getInitials('17d9d0908f454253b5337e8c1ef4b564');

Answer 5

使用Array.reduce和Array.find的一种简单的方法如果没有id，此函数将返回undefined。

var contactList = [
    {
    "id": 'e3d46de8c7194cb1a32275195c15dc07',
    "name": 'Niels Bohr',
    "num_messages": 62,
    },
    {
    'id': '7064c3f9c99743b2838bbd8eacafe0d6',
    "name": 'Max Planck',
    "num_messages": 15,
    },
    {
    "id": 'b19e575a0d3f4151a1391452d8a47a44',
    "name": 'Jane Goodall',
    "num_messages": 20,
    },
    {
    "id": '17d9d0908f454253b5337e8c1ef4b564',
    "name": "Caroline Herschel",
    "num_messages": 3,
    },
]

function getInitials(id){
  //using .find to find the element in the array
  const contact = contactList.find(contact => contact.id === id) 
  //cross checking if id is present and for that id name key is present and then using reduce function to get initials.
  return contact && contact.name && contact.name.split(' ').reduce((initial, name) => initial + name[0], '')
}

console.log(getInitials('b19e575a0d3f4151a1391452d8a47a44'))  //JG

console.log(getInitials('random'))  //undefined

Answer 6

这是在单个操作链中使用filter，map，shift和正则表达式的简洁方法。该技术可以在任意数量的空格中使用，请参见下面的示例，如果找不到联系人ID，则会返回undefined。

首先，对数组进行过滤以获取正确的ID，这将返回一个数组（可以为空），您可以在该数组上进行映射以提取带有String.match，正则表达式和Array.join的首字母缩写。然后，您将第一个元素移出以获得结果，如果没有元素，shift不会引发错误，只会返回undefined。

这里有两种可能的用于提取首字母的正则表达式：

/\b(\w)/g
/(?<=(\s+|^))(\w)/g

第一个正则表达式使用\b来匹配单词边界，而\w将匹配任何单词字符，因此正则表达式\b(\w)将捕获每个单词的第一个字符。当名称用短划线分隔时，此正则表达式将失败，因为短划线将视为单词分隔符。

第二个正则表达式将使用(?<=(\s+|^))后的正斜线匹配每个第一个单词字符，以检查空格或字符串的开头。

const contactList = [{
  "id": 'e3d46de8c7194cb1a32275195c15dc07',
  "name": '   Niels        Bohr',
  "num_messages": 62,
}, {
  'id': '7064c3f9c99743b2838bbd8eacafe0d6',
  "name": 'Max Planck    ',
  "num_messages": 15,
}, {
  "id": 'b19e575a0d3f4151a1391452d8a47a44',
  "name": '  Jane Goodall',
  "num_messages": 20,
}, {
  "id": '17d9d0908f454253b5337e8c1ef4b564',
  "name": "Caroline Herschel",
  "num_messages": 3,
}];

function getInitials(id) {
  return contactList
    .filter(contact => contact.id === id)
    .map(contact => contact.name.match(/(?<=(\s+|^))(\w)/g).join(''))
    .shift();
}

console.log(getInitials('17d9d0908f454253b5337e8c1ef4b564'));
console.log(getInitials('b19e575a0d3f4151a1391452d8a47a44'));
console.log(getInitials('7064c3f9c99743b2838bbd8eacafe0d6'));
console.log(getInitials('e3d46de8c7194cb1a32275195c15dc07'));
console.log(getInitials('123'));

Answer 7

    You have bag :
    ` for(var i; i < names.length; i++){
       initials += names[i][0]
      } `   
     1.i have to be initelased var i = 0;

除此之外，您的代码还在工作

如何从对象获取名称的缩写

7 个答案: