![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
若有定义float w; int a, b; ,则合法的switch语句是( )。
A.
switch(w) { case 1.0: printf("*\n"); case 2.0: printf("**\n"); }
B.
(a); { case 1 printf("*\n"); case 2 printf("**\n"); }
C.
switch(b) { case 1: printf("*\n"); default: printf("\n"); case 1+2: printf("**\n"); }
D.
switch(a+b); { case 1: printf("*\n"); case 2: printf("**\n"); default: printf("\n"); }