如何使用 JavaScript 从 JSON 中获取值

Question

Here we have a JSON file:

[  
   {  
      "title":"Potato and Cheese Frittata",
      "href":"http://allrecipes.com/Recipe/Potato-and-Cheese-Frittata/Detail.aspx",
      "ingredients":"cheddar cheese, eggs, olive oil, onions, potato, salt",
      "thumbnail":"http://img.recipepuppy.com/2.jpg"
   },
   {  
      "title":"Eggnog Thumbprints",
      "href":"http://allrecipes.com/Recipe/Eggnog-Thumbprints/Detail.aspx",
      "ingredients":"brown sugar, butter, butter, powdered sugar, eggs, flour, nutmeg, rum, salt, vanilla extract, sugar",
      "thumbnail":"http://img.recipepuppy.com/3.jpg"
   },
   {  
      "title":"Irish Champ",
      "href":"http://allrecipes.com/Recipe/Irish-Champ/Detail.aspx",
      "ingredients":"black pepper, butter, green onion, milk, potato, salt",
      "thumbnail":"http://img.recipepuppy.com/5.jpg"
   },
   {  
      "title":"Chocolate-Cherry Thumbprints",
      "href":"http://allrecipes.com/Recipe/Chocolate-Cherry-Thumbprints/Detail.aspx",
      "ingredients":"cocoa powder, baking powder, butter, eggs, flour, oats, salt, sugar, vanilla extract",
      "thumbnail":"http://img.recipepuppy.com/6.jpg"
   },
   {  
      "title":"Hot Spiced Cider",
      "href":"http://allrecipes.com/Recipe/Hot-Spiced-Cider/Detail.aspx",
      "ingredients":"allspice, apple cider, brown sugar, cinnamon, cloves, nutmeg, orange, salt",
      "thumbnail":"http://img.recipepuppy.com/8.jpg"
   }
]

How can i get only the titles of each results for example here I need to get only ( Potato and Cheese Frittata, Eggnog Thumbprints, Chocolate-Cherry Thumbprints,Hot Spiced Cider)

Thank you!

Answer 1

jsFiddle Demo

First, JSON is a string notation used for serializing information. It can be deserialized (parsed in JavaScript) into an object or array. What you have is the deserialized format, and as a result it is simply a plain array of objects.

As a result, the native .map ^MDN api function will work to map the .title from each object into an array of just those titles.

var titles = result.map(function(obj){ return obj.title; });

Answer 2

Try this it will give you what you want:

var a = [{ "title":"Potato and Cheese Frittata"}, {"title":"Eggnog Thumbprints" }]; 
for (var i = 0; i < a.length; i++) { 
    alert(a[i].title); 
}