源码:
List<Long> shotsIdList = result.stream().map(BandBindingVO::getRuiShotsId).distinct().collect(Collectors.toList());
List<ShotsManageDO> shotsNameList = shotsManageMapper.selectByShotIds(shotsIdList);
//第一种:for循环嵌套赋值
for (BandBindingVO bandBindingVO : result) {
for (ShotsManageDO shotsManageDO : shotsNameList) {
if (shotsManageDO.getRuiShotsId().equals(bandBindingVO.getRuiShotsId())){
bandBindingVO.setShotsArea(shotsManageDO.getShotsArea());
}
}
}
//第二种:foreach 加上lambda
result.forEach(bandBindingVO -> shotsNameList.forEach(shotsManageDO -> {
if (bandBindingVO.getRuiShotsId().equals(shotsManageDO.getRuiShotsId())) {
bandBindingVO.setShotsArea(shotsManageDO.getShotsArea());
}
}));
问题一:俩种遍历,哪种跟好?
问题二:第二种这样在foreach里面再进行foreach遍历赋值有问题吗?
如果没问题,这样写效率是更高还是更低。
问题三:如果有空可以给我讲讲for,fori,foreach的区别和各要注意什么事项吗?感谢感谢