在ES5中使用模块模式时,调用this.methodName
会在返回对象中给出methodName。但是在ES6中它现在有点不同......
旧方式(使用ES5):
var moduleOld = (function() {
//private
var privateArray = [1,2,3,4];
return {
getItemCount: function() {
return privateArray.length;
},
getTotal: function() {
return this.getItemCount();
}
};
})();
//output
console.log(moduleOld.getTotal()); //4 <-- Now, I want the same results with ES6 syntax
新方式(使用ES6):
let moduleES6 = (()=> {
//private
let privateArray = [1,2,3,4];
return {
getItemCount: ()=> {
return privateArray.length;
},
getTotal: ()=> {
return this.getItemCount();
}
};
})();
//output
console.log("es6 ", moduleES6.getTotal()); //Uncaught TypeError: this.getItemCount is not a function
有很多方法......
let moduleES6_2 = (()=> {
//private
let privateArray = [1,2,3,4];
return {
getItemCount: ()=> {
return privateArray.length;
},
getTotal: ()=> {
return moduleES6_2.getItemCount(); // I changed "this" to the module name, i.e. moduleES6_2
}
};
})();
//output
console.log("es6 calling by module name: ", moduleES6_2.getTotal()); //works! But what if I change the module's name? Then I have to also change the function call in the getTotal function.
这样,更改模块的名称不应该是一个大问题:
let moduleES6_3 = (()=> {
//private
let privateArray = [1,2,3,4];
function getItemCount() {
return privateArray.length;
}
return {
//getItemCount: getItemCount,
getTotal: ()=> {
return getItemCount(); // I am calling the private method. Not the public method!
}
};
})();
//output
console.log("es6 by private method: ", moduleES6_3.getTotal()); //works! But I don't really use the method in the return object, but rather the private declared method.
如何使用ES6访问返回对象(模块模式)中的“公共”功能?
let moduleES6 = (()=> {
//private
let privateArray = [1,2,3,4];
function getItemCount() {
return privateArray.length;
}
return {
getItemCount: ()=> {
return privateArray.length;
},
getTotal: ()=> {
return this.getItemCount();//<-- how to access the public getItemCount method?
}
};
})();
答案 0 :(得分:0)
您可以使用对象方法的简写语法,例如getItemCount()
:
let moduleES6 = (()=> {
//private
let privateArray = [1,2,3,4];
return {
getItemCount() {
return privateArray.length;
},
getTotal() {
return this.getItemCount();
}
};
})();
moduleES6.getTotal() //4