//new出一个list对象 List bookList = new ArrayList(); //for增强循环,此方法用的比较多 for(Book myBook :bookList){ System.out.println("myBook"+ myBook); }//等价于 List bookList = new ArrayList(); Book myBook;//对象 //判
常用极限 lim x → 0 sin x x = 1 \lim_{x \to 0} {\frac{\sin x}{x}}=1 limx→0xsinx=1 lim x → 0 ( x + 1 ) 1 x = e \lim_{x \to 0} {(x+1)^\frac{1}{x}}=e limx→0(x+1)x1=e lim n → ∞ a n = 1 \lim_{n \t