假设btn是获取到的按钮,点击按钮调用checkCity这样一个函数,以下写法正确的有哪些
A. btn.onclick = function(){checkCity;}
B. btn.onclick = function(){checkCity();}
C. btn.onclick = checkCity;
D. btn.onclick = checkCity()
下面代码的结果是var cars = ['bmw','qq','byd','glof']; cars.splice(2,0,'polo'); console.log(cars);
A. ["bmw", "qq", "byd", "polo", "glof"]
B. ["bmw", "qq", "polo", "glof"]
C. ["bmw", "qq", "polo", "byd", "glof"]
D. 以上都不对