# Set 没有fori循环 的遍历方式
# iterator for 循环
for (Iterator<Integer> iterator = set.iterator(); iterator.hasNext(); ) {
iterator.next();
}
# iterator while 循环
Iterator<Integer> iterator = set.iterator();
while (iterator.hasNext()) {
iterator.next();
}
# for Boost 循环
for (int item : set) {
}
# list.forEach 循环
set.forEach(item -> {
});
# list.stream().forEach 循环
set.stream().forEach(item -> {
});
# list.parallelStream().forEach 循环
set.parallelStream().forEach(item -> {
});
性能比较
每种循环各遍历50000000次 total cost time = 1475 ms
iterator for 循环 : 296 ms, 20.07%
iterator while 循环 : 300 ms, 20.34%
for Boost 循环 : 296 ms, 20.07%
list.forEach 循环 : 297 ms, 20.14%
list.stream().forEach 循环 : 195 ms, 13.22%
list.parallelStream().forEach 循环 : 88 ms, 5.97%