window.onload =function(){ var a =1; var oBtn = document.getElementById('btn');
oBtn.onclick = function(){
foo();
}
}
function foo(){ console.log(a) //Uncaught ReferenceError: a is not defined
}
為什么這段代碼訪問不了上一級的變量？
www說
2018-10-11 10:13:16