Question

C语言代码，完全看不懂提示，求大佬讲解。谢谢！

a.c: In function ‘main’:
a.c:10:14: warning: comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning [-Wparentheses]
else if (3 <f <13)
^
a.c:12:8: warning: statement with no effect [-Wunused-value]
else (f >= 13)
^
a.c:13:3: error: expected ‘;’ before ‘fm’
fm = 3.0*f-9 ;
^
a.c:6:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%lf %d",&f,&t);
^

Answer 1

第一个：else if (3 <f <13) 这个改成 else if(f>3&&f<13)
第二个：else (f >= 13)改成else if(f >= 13)
第三个是前边一行行末缺少分号";"
第四个scanf("%lf %d",&f,&t); 改成这样试试scanf("%f %d",&f,&t);