javascript - 根据数组检查输入 - Javascript

Question

我是全新的，所以请原谅任何失礼。我寻找解决方案，但找不到任何可以回答我的问题的内容，或者至少找不到任何我能理解的内容。

所以这里是:我想迭代此数组中的每个对象，并检查firstName(在本例中为“Akira”)是否与“contacts”数组中的任何firstName 匹配。在这个阶段，我只想返回对象的索引号(如果可能的话)。如果没有，请告诉我如何以最基本的、5 年前的方式做到这一点。谢谢!

var contacts = [
{
    "firstName": "Akira",
    "lastName": "Laine",
    "number": "0543236543",
    "likes": ["Pizza", "Coding", "Brownie Points"]
},
{
    "firstName": "Harry",
    "lastName": "Potter",
    "number": "0994372684",
    "likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
    "firstName": "Sherlock",
    "lastName": "Holmes",
    "number": "0487345643",
    "likes": ["Intriguing Cases", "Violin"]
},
{
    "firstName": "Kristian",
    "lastName": "Vos",
    "number": "unknown",
    "likes": ["Javascript", "Gaming", "Foxes"]
}

function lookUpProfile(firstName, prop){
  for (var i = 0; i < contacts.length; i++) {
   if (contacts[i][firstName] == firstName){
      return i; 
   } 
  }   
}

lookUpProfile("Akira", "likes");

Answer 1

您的代码有一个错误，您的联系人变量没有关闭“]”，访问对象属性时也使用代码contacts[i][“firstname”]

var contacts = [
{
    "firstName": "Akira",
    "lastName": "Laine",
    "number": "0543236543",
    "likes": ["Pizza", "Coding", "Brownie Points"]
},
{
    "firstName": "Harry",
    "lastName": "Potter",
    "number": "0994372684",
    "likes": ["Hogwarts", "Magic", "Hagrid"]
},
{
    "firstName": "Sherlock",
    "lastName": "Holmes",
    "number": "0487345643",
    "likes": ["Intriguing Cases", "Violin"]
},
{
    "firstName": "Kristian",
    "lastName": "Vos",
    "number": "unknown",
    "likes": ["Javascript", "Gaming", "Foxes"]
}];

function lookUpProfile(firstName, prop){
  var ret = -1;
  for (var i = 0; i < contacts.length; i++) {
   if (contacts[i]["firstName"] == firstName){
      ret = i; 
   } 
  }
  console.log(ret);
}


  lookUpProfile("Akira", "likes");