我不知道为什么我的方法不起作用（如果声明）

Question

This program classifies quadrilaterals. I'm not sure why my method just won't work, the coordinates I used were (08,4),nd (5,5). All my other methods work so I don't think its because of my formula.

Answer 1

if((ab == bc && cd == da) || (bc == cd && da == ab))

in your case any rectangle is kite ( 1 + 2 == 1 + 2)

Answer 2

if((ab + bc) == (cd + da) || (bc + cd) == (da + ab)){}

如果不放在方括号中，则编译器将查看元素的优先级。