摘要： public class calc{public String oper(float a,float b,char c){float add=a+b;float jian=a-b;float chen=a*b;float chu=a/b;switch(c){case '+':return "想加的结果为："+add;case '-':return "想减的结果为："+jian;case '*':return "想乘的结果为："+chen;case '/':return & 阅读全文