Javascript擴展不起作用

Question

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script> 
<script> 
$(document).ready(function(){ 
var animal = { 
    type: "mammal" 
}; 

var dog = { 
    sound: "bark" 
}; 

dog.extends(animal); 
alert(dog.type); 
}); 
</script> 

上面的代碼沒有提醒，並且錯誤地指出未定義不是函數。任何想法爲什麼？

Answer 1

試試這個

$(document).ready(function(){ 
    var animal = { 
     type: "mammal" 
    }; 

    var dog = { 
     sound: "bark" 
    }; 

    $.extend(dog, animal); 
    alert(dog.type); 
    }); 

http://jsfiddle.net/auekn4f1/