本文通过举例，由浅入深的讲解了解决js函数闭包内存泄露问题的办法，分享给大家供大家参考，具体内容如下
原代码：
<span style="font-size:14px;">function Cars(){this.name = "Benz";this.color = ["white","black"];
}
Cars.prototype.sayColor = function(){var outer = this;return function(){return outer.color};
};var instance = new Cars();
console.log(instance.sayColor()())</span>优化后：
<span style="font-size:14px;">function Cars(){this.name = "Benz";this.color = ["white","black"];
}
Cars.prototype.sayColor = function(){var outerColor = this.color; //保存一个副本到变量中return function(){return outerColor; //应用这个副本};outColor = null; //释放内存
};var instance = new Cars();
console.log(instance.sayColor()())</span>举例：
<span style="font-size:14px;">function inheritPrototype(subType,superType){var prototype = Object(superType.prototype);prototype.constructor = subType;subType.prototype = prototype;
}function Cars(){this.name = "Benz";this.color = ["white","black"];
}
Cars.prototype.sayColor = function(){var outer = this;return function(){return outer.color;};
};function Car(){Cars.call(this);this.number = [321,32];
}
inheritPrototype(Car,Cars);
Car.prototype.sayNumber = function(){var outer = this;return function(){return function(){return outer.number[outer.number.length - 1];}};
};var instance = new Car();
console.log(instance.sayNumber()()());</span>首先，该例子组合使用了构造函数模式和原型模式创建Cars 对象，并用了寄生组合式继承模式来创建Car 对象并从Cars 对象获得属性和方法的继承；
其次，建立一个名为instance 的Car 对象的实例；instance 实例包含了sayColor 和sayNumber 两种方法；
最后，两种方法中，前者使用了一个闭包，后者使用了两个闭包，并对其this 进行修改使其能够访问到this.color 和this.number。
这里存在内存泄露问题，优化后的代码如下：
<span style="font-size:14px;">function inheritPrototype(subType,superType){var prototype = Object(superType.prototype);prototype.constructor = subType;subType.prototype = prototype;
}function Cars(){this.name = "Benz";this.color = ["white","black"];
}
Cars.prototype.sayColor = function(){var outerColor = this.color; //这里return function(){return outerColor; //这里};this = null; //这里
};function Car(){Cars.call(this);this.number = [321,32];
}
inheritPrototype(Car,Cars);
Car.prototype.sayNumber = function(){var outerNumber = this.number; //这里return function(){return function(){return outerNumber[outerNumber.length - 1]; //这里}};this = null; //这里
};var instance = new Car();
console.log(instance.sayNumber()()());</span>