import java.math.BigDecimal;
public class test {
public static void main(String[] args) {
float a = 1.1f;
float b = 2.2f;
test t = new test ();
System.out.println(t.add(a,b));
System.out.println(t.sub(a,b));
System.out.println(t.mul(a,b));
System.out.println(t.div(a,b));
System.out.println(t.round(a));
}
public float add(float v1,float v2){//加法
BigDecimal b1 = new BigDecimal(Float.toString(v1));
BigDecimal b2 = new BigDecimal(Float.toString(v2));
return b1.add(b2).floatValue();
}
public float sub(float v1,float v2){//减法
BigDecimal b1 = new BigDecimal(Float.toString(v1));
BigDecimal b2 = new BigDecimal(Float.toString(v2));
return b1.subtract(b2).floatValue();
}
public float mul(float v1,float v2){//乘法
BigDecimal b1 = new BigDecimal(Float.toString(v1));
BigDecimal b2 = new BigDecimal(Float.toString(v2));
return b1.multiply(b2).floatValue();
}
public float div(float v1,float v2){//除法
BigDecimal b1 = new BigDecimal(Float.toString(v1));
BigDecimal b2 = new BigDecimal(Float.toString(v2));
return b1.divide(b2,3,BigDecimal.ROUND_HALF_UP).floatValue();
}
public float round(float v){//截取3位
BigDecimal b = new BigDecimal(Float.toString(v));
BigDecimal one = new BigDecimal("1");
return b.divide(one,3,BigDecimal.ROUND_HALF_UP).floatValue();
}
}
