如何遍历一个HashMap

以下是两种方法遍历HashMap的代码示例

方法

Map map = new HashMap(); mapput(a ); mapput(b ); mapput(c ); mapput(d ); mapput(e ); for (Iterator iter = mapkeySet(erator(); iterhasNext();) { Object key = iternext(); Object val = mapget(key); Systemoutprintln(key:+key); Systemoutprintln(value:+val); }

方法

view sourceprint?Map map = new HashMap();

mapput(a );

mapput(b );

mapput(c );

mapput(d );

mapput(e );

for (Iterator iter = mapentrySet(erator(); iterhasNext();) {

MapEntry entry = (MapEntry) iternext();

Object key = entrygetKey();

Object val = entrygetValue();

Systemoutprintln(key:+key);

Systemoutprintln(value:+val);

}

view sourceprint?<%

Map<String Integer> map = (Map<String Integer>) sessiongetAttribute(UserInfo);

outprintln(map == null);

if (map == null)

{

map = new HashMap<String Integer>();

outprintln(map == null);

mapput(steden );

mapput(steden );

mapput(steden );

mapput(steden );

}

sessionsetAttribute(UserInfo map);

for(MapEntry<String Integer> item : mapentrySet())

{

outprintln(itemgetKey());

outprintln(itemgetValue());

outprintln(<br />);

}

%>

性能从低到高

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