1)List与ArrayList的关系?
2)for (Line line : lines)这是什么语法?Java教程中没有查到过。//线类
class Line {
float xStart,yStart,xStop,yStop;
public Line(float xStart, float yStart, float xStop, float yStop) {
this.xStart = xStart;
this.yStart = yStart;
this.xStop = xStop;
this.yStop = yStop;
}
}private List<Line> lines = new ArrayList<Line>();private void drawChssboardLines(Canvas canvas) {
for (Line line : lines) {
canvas.drawLine(line.xStart, line.yStart, line.xStop, line.yStop, paint);
}
}
2)for (Line line : lines)这是什么语法?Java教程中没有查到过。//线类
class Line {
float xStart,yStart,xStop,yStop;
public Line(float xStart, float yStart, float xStop, float yStop) {
this.xStart = xStart;
this.yStart = yStart;
this.xStop = xStop;
this.yStop = yStop;
}
}private List<Line> lines = new ArrayList<Line>();private void drawChssboardLines(Canvas canvas) {
for (Line line : lines) {
canvas.drawLine(line.xStart, line.yStart, line.xStop, line.yStop, paint);
}
}
2.java foreach语法
for(Line l:list){
...
}相当于
for(int i=0;i<list.size();i++){
Line l=list.get(i);
...
}
这就是遍历赋值,多结合例子用用就明白了
public class ArrayList<E> extends AbstractList<E>
public abstract class AbstractList<E> extends AbstractCollection<E> implements List<E>