用for-each 边遍历ArrayList 边修改时:
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public static void main(String[] args) {
ArrayList<String> list = new ArrayList<>();
list.add( "aa" );
list.add( "bb" );
list.add( "cc" );
list.add( "dd" );
System.out.println(list);
for (String s : list) {
if (s.equals( "dd" )) {
list.remove(s);
}
}
System.out.println(list);
}
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会报错
可以改用如下方式:
① 用迭代器 iterator进行遍历删除
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public static void main(String[] args) {
ArrayList<String> list = new ArrayList<>();
list.add( "aa" );
list.add( "bb" );
list.add( "cc" );
list.add( "dd" );
System.out.println(list);
Iterator<String> iterator = list.iterator();
while (iterator.hasNext()) {
String next = iterator.next();
if (next.equals( "dd" )) {
iterator.remove();
}
}
System.out.println(list);
}
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②:使用最原始的 for循环
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public static void main(String[] args) {
ArrayList<String> list = new ArrayList<>();
list.add( "aa" );
list.add( "bb" );
list.add( "cc" );
list.add( "dd" );
System.out.println(list);
for ( int i = 0 ; i < list.size(); i++) {
String s = list.get(i);
if (s.equals( "dd" )) {
list.remove(s);
}
}
System.out.println(list);
}
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③:采用jdk8 Collection中新增的方法removeIf (个人推荐,简洁快捷新特性)
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public static void main(String[] args) {
ArrayList<String> list = new ArrayList<>();
list.add( "aa" );
list.add( "bb" );
list.add( "cc" );
list.add( "dd" );
System.out.println(list);
list.removeIf(next -> next.equals( "dd" ));
System.out.println(list);
}
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以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:https://www.cnblogs.com/convict/p/13210740.html