我应该检查该值,如果不是该值,则不更新该值。如果输入有效,那么我将其返回。我现在被困在这里。有人能帮我吗。我写了一些代码,但是没有用。
public class Student {
private int studentId;
private String name;
private double grade;
private double multiplier;
public double getMultiplier() {
return multiplier;
}
/**
* The setter for the multiplier must check that the value is either 1.08 *
* 1.06 or 1.08 or 1.06
*
* If not, then do not update the value
*
* @param multiplier
* @return if the input was valid
*/
public boolean setMultiplier(double multiplier) {
if( multiplier == 1.08 * 1.06 || multiplier == 1.08 || multiplier == 1.06 ) {
}
return multiplier;
}
setter
应该更新一个值,并且不返回值(getter
的角色),因此它的返回类型应该为void
而不是boolean
public void setMultiplier(double multiplier) {
if( multiplier == 1.08 * 1.06 || multiplier == 1.08 || multiplier == 1.06 ) {
this.multiplier = multiplier;
}
}
我认为您只是忘记了实际设置新值。
因此,如果您这样做,它应该可以工作:
public void setMultiplier(double multiplier) {
if( multiplier == 1.08 * 1.06 || multiplier == 1.08 || multiplier == 1.06 ) {
this.multiplier = multiplier;
}
}
此外,setter通常是void
而不是布尔值,并且没有返回值。
public void setMultiplier(double multiplier) {
if (multiplier == 1.08 * 1.06 || multiplier == 1.08 || multiplier == 1.06) {
this.multiplier = multiplier; //here
}
throw new IllegalArgumentException("exception message");
}
}
您忘记编写类的字段变量。我的问题是,您是返回布尔值还是引发异常?
提示:我不会在代码中的任何地方分发我的常量1.06或1.08。您可以如下定义它:
public class student {
private static final double MEANINGFUL_NAME_0 = 1.06;
private static final double MEANINGFUL_NAME_1 = 1.08;
// other code below
}