【发布时间】:2016-05-18 08:07:20
【问题描述】:
我正在为灯泡做一个课程,我必须让它处于开/关状态,无论它是否烧坏,以及它的颜色。无论出于何种原因,我得到了正确的切换,但是我的 toString 打印了错误的答案,我不知道为什么。我不习惯使用布尔值,所以我的代码可能不支持我的逻辑。有人可以帮忙吗?
代码如下:
public class Light
{
// Variables that will be initialized in the Light constructors.
private boolean on;
private boolean burntOut;
private String color = "";
// Default constructor that sets the bulb to on, not burnt out, and "white".
public Light()
{
on= true;
burntOut = false;
color = "white";
}
// This constructor sets the variable "on" to the parameter o. The burntOut
// variable is set to the parameter b. If burntOut
// is true, on is set to false, no matter what value is stored in o.
// The color variable is set to the parameter c only if c is "red", "green"
// or "blue". The constructor ignores the case of the value in c. If c holds
// any value other than "red", "green" or "blue", the constructor sets
// color to "white".
public Light(boolean o, boolean b, String c)
{
on = o;
burntOut=b;
if(burntOut=true){
on = false;
}
else{
on= o;
}
if(c.equalsIgnoreCase("red")){
color = "red";
}
if(c.equalsIgnoreCase("blue")){
color = "blue";
}
if (c.equalsIgnoreCase("green")){
color="green";
}
else {
color = "white";
}
}
// The toString method returns a String with the Light in the format:
// off red burnt out
// on green not burnt out
//
// Notice there is one space between "off"/"on" and the value for color,
// and a tab before the "burnt out" or "not burnt out".
public String toString()
{
String x ="";
if(on = true){
x+="on" + " ";
}
if(on = false){
x+= "off" + " ";
}
x+= color;
if (burntOut = false){
x+="\t" + "not burnt out";
}
if(burntOut = true){
x+= "\t" + "burnt out";
}
return x;
}
这是项目允许我运行以显示我的结果的测试:
> run Light
1。测试灯() * PASS: on 设置正确 (true) PASS:burntOut 设置正确(假) PASS:颜色设置正确(白色) * FAIL: toString 不能按预期工作(白色烧坏)
- 测试灯(布尔 b,布尔 o,字符串 c) * PASS: on 设置正确 (false) PASS:burntOut 设置正确(true) PASS:颜色设置正确(绿色) * FAIL: toString 不能按预期工作(绿色烧坏)
【问题讨论】:
-
=用于赋值。 -
==,而不是=。或者,更好的是if (on) { ... } else { ... }。 -
这很有意义
-
这是你犯错的地方,if(burntOut=true){ on = false; } 应该是 if(burntOut == true){ on = false; } 检查每一步是否正确。
标签: java string boolean tostring