在 Node.JS 示例代码中,我发现了如下代码块。
var messageReceivedCallBack = {
onMessageReceived: function (message) {
console.log('Message received ' + message);
}
};
这段代码是什么意思?具体来说,我无法理解带有冒号(':')的部分
最佳答案
这是一个对象字面量。这不是一个变量,它是一个属性名称:
var foo = {
a: 1,
b: 2
};
等同于:
var foo = {};
foo.a = 1;
foo.b = 2;
同样:
var foo = {
a: function () {}
};
等同于:
var foo = {};
foo.a = function () {};
因此如下:
var messageReceivedCallBack = {
onMessageReceived: function (message) {
console.log('Message received ' + message);
}
};
只是这样做:
var messageReceivedCallBack = {};
messageReceivedCallBack.onMessageReceived = function (message) {
console.log('Message received ' + message);
};
关于javascript - "variable : function(){}"是什么意思?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38783036/