如何根據給定的信息找到一個數組對象？

Question

我在AngularJS控制器這樣的數組：

$scope.persons = [{name:'Joey', age:'27'},{name:'Lucy', age:'22'}] 

我有一個名爲「露西」，我怎麼能得到這個名字的年齡在控制器（未在HTML）？

Answer 1

我在這裏創建了一個簡單的結果，只是年齡，以及多個結果。

這也可以一個過濾器，這是在這裏的角部位文件內實施：https://docs.angularjs.org/api/ng/filter/filter

https://plnkr.co/edit/OFRMzpQrZfTOnaFyJP7Z?p=info

angular.module('plnk',[]).controller('plnkCtrl', function($scope){ 

    // Note, I added a second Joey here to test the multiple function. 
    // For output, check the browser console. 

    $scope.persons = [{name:'Joey', age:'27'},{name:'Joey', age:'28'},{name:'Lucy', age:'22'}] 

    console.log('Single -> ', getAgeSingle('Lucy')); 
    console.log('Multiple ->',getAgeMultiple('Joey')); 

    function getAgeMultiple(personLookup) { 

    var results = []; 
    angular.forEach($scope.persons,function(person){ 
     if (person.name === personLookup) { 
     results.push(person); 
     // or results.push(person.age) for age only 
     } 
    }); 
    return results; 

    } 

    function getAgeSingle(personLookup) { 
    var result = ''; 
    angular.forEach($scope.persons,function(person){ 
     if (person.name === personLookup && !result) { 
     result = person.age; 
     } 
    }); 
    return result; 
    } 

}); 

Answer 2

如果通過範圍要循環：

$scope.persons = [{name:'Joey', age:'27'}, {name:'Lucy', age:'22'}] 

function getAge(name) { 
    angular.forEach($scope.persons, function (value, index) { 
     if (value.name === name) { 
      return parseInt(value.age, 10); 
     } 
    }); 
    return undefined; 
} 

的HTML方式：

<div ng-app="myApp" ng-controller="MainCtrl"> 
    <table> 
     <tr ng-repeat="person in persons"> 
      <td>Name: {{person.name}} Age: {{person.age}}</td> 
     </tr> 
    </table> 
</div> 

JS：

var app = angular.module('myApp', []); 

app.controller('MainCtrl', function ($scope) { 
    $scope.persons = [{name:'Joey', age:'27'}, {name:'Lucy', age:'22'}]; 
}); 

Answer 3

只是循環陣列上，並檢查，這樣：

function getAge(name) 
{ 
    for (var i = 0; i < $scope.persons.length; i++) 
    { 
    var person = $scope.persons[i]; 
    if (person.name === name) 
    { 
     return parseInt(person.age, 10); 
    } 
    } 

    return undefined; 
} 

這有幾個警告 - 如果你有欺騙，你只會得到第一個，它會在線性時間運行。如果你控制數據源，最好使用JS對象/ hashmap/dictionary /無論你想調用它。