向上取整 var a = 23.2325236 var abc = Math.ceil(a); //注意:Math.ceil(a)不要单独写一行,否则向上取整失败 abc = 24; 向下取整 var a = 23.2325236 var abc = Math.floor(a)//注意: Math.floor(a) 不要单独写一行,否则向下取整失败 abc = 23; 四舍五入 Math.round(7/2);…
在erlang的API中,erlang:trunc/1 是就近取整,erlang:round/1是四舍五入的, 整理下:对于正数的向上和向下取整, %% 向上取整 ceil(N) -> T = trunc(N), case N == T of true -> T; false -> 1 + T end. %% 向下取整 floor(X) -> T = trunc(X), case (X < T) of true -> T - 1; _ -> T end. 而对于负…