尝试Array.prototype.some ()

MDN Array.prototype.some

    function isBiggerThan10(element, index, array) {
      return element > 10;
    }
    [2, 5, 8, 1, 4].some(isBiggerThan10);  // false
    [12, 5, 8, 1, 4].some(isBiggerThan10); // true

如果可能的话，使用es6

carBrands.filter(carBrand => carBrand.name === carX.name).length > 0

如果这是真的，那就有相似之处

为什么不使用javascript数组的indexOf方法呢?

看看这个:MDN indexOf Arrays

只是做的事:

carBrands.indexOf(car1);

它将返回car1的索引(在数组中的位置)。如果在数组中没有找到car1，它将返回-1。

http://jsfiddle.net/Fraximus/r154cd9o

Edit: Note that in the question, the requirements are to check for the same object referenced in the array, and NOT a new object. Even if the new object is identical in content to the object in the array, it is still a different object. As mentioned in the comments, objects are passed by reference in JS and the same object can exist multiple times in multiple structures. If you want to create a new object and check if the array contains objects identical to your new one, this answer won't work (Julien's fiddle below), if you want to check for that same object's existence in the array, then this answer will work. Check out the fiddles here and in the comments.

我使用下划线javascript库来调整这个问题。

function containsObject(obj, list) {
 var res = _.find(list, function(val){ return _.isEqual(obj, val)});
 return (_.isObject(res))? true:false;
}

关于上面例子中使用的下划线函数，请参考underscore.js文档。

注意:这不是一个纯javascript解决方案。为了教育目的而共享。

可以这样说:

function containsObject(obj, list) {
    var i;
    for (i = 0; i < list.length; i++) {
        if (list[i] === obj) {
            return true;
        }
    }

    return false;
}

在本例中，containsObject(car4, carBrands)为真。删除carBrands.push(car4);调用，它将返回false。如果你后来扩展到使用对象来存储这些其他car对象，而不是使用数组，你可以使用这样的东西:

function containsObject(obj, list) {
    var x;
    for (x in list) {
        if (list.hasOwnProperty(x) && list[x] === obj) {
            return true;
        }
    }

    return false;
}

这种方法也适用于数组，但是当用于数组时，它会比第一种方法慢一些。

最近被FP bug咬了一口，阅读了许多关于函数式范式如何与Javascript完美契合的精彩描述

为了完整起见，我复制了代码，并提出了两种可以实现此功能的方法。

    var carBrands = [];

  var car1 = {name:'ford'};
  var car2 = {name:'lexus'};
  var car3 = {name:'maserati'};
  var car4 = {name:'ford'};
  var car5 = {name:'toyota'};

  carBrands.push(car1);
  carBrands.push(car2);
  carBrands.push(car3);
  carBrands.push(car4);

  // ES6 approach which uses the includes method (Chrome47+, Firefox43+)

  carBrands.includes(car1) // -> true
  carBrands.includes(car5) // -> false

如果你需要支持旧的浏览器使用polyfill，似乎IE9+和Edge不支持它。位于MSDN页面的填充部分

或者，我想对cdhowie提出一个更新的答案

// ES2015 syntax
function containsObject(obj, list) {

    return list.some(function(elem) {
      return elem === obj
    })
}

// or ES6+ syntax with cool fat arrows
function containsObject(obj, list) {

    return list.some(elem => elem === obj)
}