scanner没创建完成吧,后面的括号里还有个System.in我记得
public static void main(String[] args) {
Scanner scanner=new Scanner(System.in);
System.out.println("请输入身高");
double height=scanner.nextDouble();
if(height>=155&&height<160){
System.out.println("155~160对应的衣服尺码是S");
}else if(height>=160&&height<165){
System.out.println("160~165对应的衣服尺码是M");
}else if(height>=165&&height<170){
System.out.println("165~170对应的衣服尺码是L");
}else if(height>=170&&height<175){
System.out.println("170~175对应的衣服尺码是XL");
}else if(height>175){
System.out.println("175以上对应的衣服尺码是XXL");
}
}