The hasOwnProperty method returns true if the object has a property of the specified name, false if it does not. This method does not check if ... ... <看更多>

for(var i in foo) {. if (foo.hasOwnProperty(i)) {. console.log(i);. } } Sign up for free to join this conversation on GitHub. Already have an account? ... <看更多>

hasOwnProperty 是JavaScript 中唯一一個處理屬性但是不找原型鏈的函式。 // 修改Object.prototype Object.prototype.bar = 1; var foo = {goo: undefined}; foo.bar; ... ... <看更多>

How to check if a property exists in an object in JavaScript by using the hasOwnProperty() method, the in operator, and comparing with undefined. ... <看更多>

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