Question

我想在对象数组中搜索字符串并返回匹配的对象。试着在这里使用es6。

请在下面找到代码：

＆＃13;

// set of keys
const defConfigs = [{
    title: "Id",
    key: "id"
  },
  {
    title: "Tenant",
    key: "tenant"
  },
  {
    title: "Opened",
    key: "opened"
  },
  {
    title: "Title",
    key: "title"
  },
  {
    title: "Status",
    key: "status"
  },
  {
    title: "Priority",
    key: "priority"
  }
];

// items as array of objects
const items = [{
    id: "INC000000004519",
    title: "Follow-up after INC000000004507",
    description: null,
    urgency: "4-Low",
    severity: "4-Minor/Localized"
  },
  {
    id: "INC000000004515",
    title: "network drop:↵Network Element CVU042_Johnstown get unsynchronized↵Network Element CVU043_Redman",
    description: "Client network drop since 08:51 until 09:06, pleas…ork Element CVU045_North_Salem get unsynchronized",
    urgency: "3-Medium",
    severity: "3-Moderate/Limited"
  },
  {
    id: "INC000000004088",
    title: "not able to schedule GPEH in ABC",
    description: "Contact: abc@xyz.com↵+14692669295↵…WCDMA, we are not able to schedule GPEH in ABC. I",
    urgency: "4-Low",
    severity: "4-Minor/Localized"
  },
  {
    id: "INC000000004512",
    title: "SR Updated - P3 - 2018-0427-0305 - xyz TELECOMMUNICATIONS ROMANIA S.R.L - Lost the  mng connect",
    description: null,
    urgency: "4-Low",
    severity: "4-Minor/Localized"
  },
  {
    id: "INC000000004414",
    title: "Acme incident 1 title",
    description: "Acme incident 1 description",
    urgency: "2-High",
    severity: "1-Extensive/Widespread"
  }
];


// trying to search for string in keys defined in defConfigs
items.filter(item =>
  defConfigs.forEach((def) => {
    if (def.key in item) {
      return (item[def.key].toString().toLowerCase().match('low').length > 1);
    }
  }));

// always throws an error Uncaught TypeError: Cannot read property 'length' of null
console.log(items);

＆＃13;

这里有3个字符串＆＃34;低＆＃34;并且我希望代码返回第一个项目（＆＃34;标题＆＃34;＆＃34; Fol 低 - ＆＃34之后;）;但是match永远不会回来。

如何在对象数组中搜索字符串并返回这些对象？

Answer 1

如果没有匹配项，

String.prototype.match()函数将返回null，因此您需要检查此案例。接下来，您可以使用Array.prototype.some()函数来验证阵列中至少有一个项目是否满足您的条件。例如：

items.filter(item =>
  // check if at least one key from `defConfigs` on `item` matches 'low'
  defConfigs.some((def) => {
    if (def.key in item) {
      const matched = item[def.key].toString().toLowerCase().match('low')
      // return true if item matched
      return !!matched
   }
   // match not found by default
   return false
}));

Answer 2

如果你仔细观察，你会注意到：

您不会检查.match是否匹配（在不匹配时返回null;对null.length进行测试会产生错误）
您正在检查match.length > 1 ...您正在使用的语法将返回一个只有一个项目的数组或null
您缺少.filter
您不会将.filter的返回值分配给任何变量

以下是您需要做的事情：

var filteredItems = items.filter(function (item) {
    return defConfigs.some(function (def) {
        return (def.key in item)
            ? item[def.key].toString().toLowerCase().match('low') !== null
            : false;
    });
});
console.log(filteredItems);

Answer 3

找不到匹配项时，

String.prototype.match()将返回null。如果希望匹配结果为null，则应严格将匹配结果与null进行比较。

你应该看看Array.prototype.filter。它返回一个新数组，不会修改作为参数传递的引用，原始项目是安全的（暂时）。

Answer 4

单词＆＃34; low＆＃34;只能在紧急度属性中找到，而 defConfigs 数组不具有此字段
因此，在将其添加到阵列后，请执行以下操作：

let newItems=items.filter(item => {


    let count= defConfigs.reduce((acc, def) => {

        if (def.key in item) {
            let arr = item[def.key].toString().toLowerCase().match(/low/gi)
            return acc + (arr ? 1 : 0);
        }
        else {

            return acc;
        }
    }, 0)

    return count >0
});

console.log(newItems);

首先为过滤后的数据 newItems
然后我使用 reduce 函数来获取整个对象是否匹配
最后在匹配函数

/ low / gi

Answer 5

在if语句if (def.key in item)中，它将检查def.key的值是否等于item中属性的名称。要完成您的想法，请参阅以下代码中的注释：

// set of keys
const defConfigs = [{title: "Id", key: "id"},
{title: "Tenant", key: "tenant"},
{title: "Opened", key: "opened"},
{title: "Title", key: "title"},
{title: "Status", key: "status"},
{title: "Priority", key: "priority"}];

// items as array of objects
const items = [{id: "INC000000004519", title: "Follow-up after INC000000004507", description: null, urgency: "4-Low", severity: "4-Minor/Localized"},
{id: "INC000000004515", title: "network drop:↵Network Element CVU042_Johnstown get unsynchronized↵Network Element CVU043_Redman", description: "Client network drop since 08:51 until 09:06, pleas…ork Element CVU045_North_Salem get unsynchronized", urgency: "3-Medium", severity: "3-Moderate/Limited"},
{id: "INC000000004088", title: "not able to schedule GPEH in ABC", description: "Contact: abc@xyz.com↵+14692669295↵…WCDMA, we are not able to schedule GPEH in ABC. I", urgency: "4-Low", severity: "4-Minor/Localized"},
{id: "INC000000004512", title: "SR Updated - P3 - 2018-0427-0305 - xyz TELECOMMUNICATIONS ROMANIA S.R.L - Lost the  mng connect", description: null, urgency: "4-Low", severity: "4-Minor/Localized"},
{id: "INC000000004414", title: "Acme incident 1 title", description: "Acme incident 1 description", urgency: "2-High", severity: "1-Extensive/Widespread"}];


// trying to search for string in keys defined in defConfigs
items.filter(item =>
defConfigs.forEach((def) => {
  //iterate through all attributes in the object
  for(var key in item){
    //check if the attribute exists, if it has the method 'indexOf' (if it's a string), and that it has def.key in the string
    if (item[key] && item[key].indexOf && item[key].indexOf(def.key)!= -1) {
      //match only accepts regular expressions which are signified in JS by enclosing the expression with forward slashes
      return (item[def.key].toString().toLowerCase().match(/low/).length >1);
    }
   }
}));

javascript - 在对象数组中搜索字符串

5 个答案: