排序数组列表中的一个对象的double值 [英] Sorting a double value of an object within an arrayList
问题描述
附加的是我的代码,如果有人可以指出我正确的方向,我将不胜感激。
public class染色体
{
公开基因[]基因;
公开双倍;
public Chromosome(int l)
{
genes = new Gene [l];
}
public int getLength()
{
return genes.length;
public void printChromo()
{
for(int i = 0; i< this.genes.length; i ++)
{
System.out.println(+ this.genes [i] .teacher +,+
this.genes [i] .lecture +,+
this.genes [i] .room +,+
this.genes [i] .time +);
}
}
public void setScore(double score)
{
this.score = score;
}
public double getScore()
{
return this.score;
}
}
不知道这有什么区别,但得分只能是在0.0到1.0之间的两倍之间
要使用 比较器
:
Collections.sort(myList,new Comparator< Chromosome>(){
@Override
public int compare(chromosome c1,染色体c2){
返回Double.compare(c1.getScore(),c2.getScore());
}
});
如果您打算排序许多列表
以这种方式,我建议有染色体
实现 可比较的
界面(在这种情况下,您可以简单地调用 Collections.sort(myList)
,而不需要指定一个明确的比较器
)。
I'm trying to sort my custom class chromosome by the value of their score attribute which is a double. These chromosomes are stored within an ArrayList. I know I have to use a comparator but I've read so many differing opinions online in the last hour that I'm utterly confused.
Attached is my code, if someone could point me in the right direction I would be much appreciated.
public class Chromosome
{
public Gene[] genes;
public double score;
public Chromosome(int l)
{
genes = new Gene[l];
}
public int getLength()
{
return genes.length;
}
public void printChromo()
{
for(int i=0;i<this.genes.length;i++)
{
System.out.println(""+this.genes[i].teacher+","+
this.genes[i].lecture+","+
this.genes[i].room+","+
this.genes[i].time+"");
}
}
public void setScore(double score)
{
this.score=score;
}
public double getScore()
{
return this.score;
}
}
Don't know this make a difference but the score can only be a double between and including 0.0 to 1.0
To use a Comparator
:
Collections.sort(myList, new Comparator<Chromosome>() {
@Override
public int compare(Chromosome c1, Chromosome c2) {
return Double.compare(c1.getScore(), c2.getScore());
}
});
If you plan on sorting numerous List
s in this way I would suggest having Chromosome
implement the Comparable
interface (in which case you could simply call Collections.sort(myList)
, without the need of specifying an explicit Comparator
).
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