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>

if ( !Object.prototype.hasOwnProperty ) {. Object.prototype.hasOwnProperty = function(prop) {. var proto = obj.__proto__ || obj.constructor.prototype;. ... <看更多>

Use the hasOwnProperty() method. Use the in operator. Compare property with undefined . Use the hasOwnProperty() method. The JavaScript Object. ... <看更多>

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有時要將JS 物件轉成其他資料結構，所以需要迭代物件中的所有property，過去會用for-in 陳述句，但只想列舉own property，就必須用hasOwnProperty() ... ... <看更多>