public static void operateString(String s) {
s.replace("j", "i");
}
public static void operateStringBuffer(StringBuffer sb) {
sb.append("C");
}
public static void main(String args[]) {
String sa = new String("java");
StringBuffer sba = new StringBuffer("java");
operateString(sa);
operateStringBuffer(sba);
System.out.println(sa);
System.out.println(sba);
}
}
絳旀寰堢畝鍗曪細
java
javaC
鍘熷垯錛?br /> 1.String鏄笉鍙彉瀵硅薄錛?span class="tpc_content">public final class String extends Object
2.java涓彧鏈夊間紶閫?span class="tpc_content">
replace鍑芥暟婧愮爜涓細
public String replace(char oldChar, char newChar) {
...
return new String(0, len, buf);
}
榪斿洖鐨勬槸鍙︿竴涓猄tring瀵硅薄銆?br /> 鑰屽湪涓婇潰鐨?/em>operateString鏂規硶涓紝鏄棤榪斿洖鍊肩殑錛屾柊浜х敓鐨凷tring瀵硅薄琚涪寮冧簡錛岃宻a浠嶇劧鎸囧悜鏈鍒濈殑閭ｄ釜String瀵硅薄銆?br />
絎簩涓緥瀛愶細
public class Test2 {
public static void operate(StringBuffer x, StringBuffer y) {
x.append(y);
y = x;
}
public static void main(String args[]) {
StringBuffer buffA = new StringBuffer("a");
StringBuffer buffB = new StringBuffer("b");
operate(buffA, buffB);
System.out.println(buffA + "," + buffB);
}
}
絳旀鏄細
ab,b
寮濮嬫椂a銆亁鎸囧悜鍚屼竴涓猄tringBuffer瀵硅薄(榪欓噷縐板畠涓哄璞?)錛屽畠鐨勫兼槸"a"錛?br /> b銆亂鎸囧悜鍚屼竴涓猄tringBuffer瀵硅薄錛屽畠鐨勫兼槸"b"銆?br /> 鎵цx.append(y)鏃訛紝瀵硅薄1鐨勫艱鏀瑰彉錛屽彉涓?ab"錛?br /> 鑰屾墽琛寉=x鏃訛紝鍙橀噺y鎸囧悜琚敼鍙橈紝鎸囧悜浜嗗拰x鍚屼竴涓猄tringBuffer瀵硅薄銆備絾鏄彉閲廱鐨勬寚鍚戣繕鏄病鏈夋敼鍙橈紝鎵浠ヤ粛鐒朵負"b"
]]>
select a.*, rownum r
from (select * from lg_order o order by o.order_id) a
where rownum <= 20
and rownum >= 10
select *
from (select a.*, rownum r
from (select * from lg_order o order by o.order_id) a
where rownum <= 20) b
where r >= 10
select *
from (select rid
from (select rownum rn, rid
from (select rowid rid from lg_order o order by o.order_id)
where rownum <= 20)
where rn >= 10) t1,
lg_order t2
where t2.rowid = t1.rid
絎竴鍙ユ槸閿欒鐨?鐢變簬rownum鏄竴涓繪槸浠?寮濮嬬殑浼垪錛孫racle 璁や負榪欑鏉′歡涓嶆垚绔嬶紝鏌ヤ笉鍒拌褰?
鎵ц欏哄簭浠庡唴鍒板錛屼粠鍙沖埌宸?
鐩存帴鍙栫墿鐞嗗湴鍧鏈蹇?br />
涔嬪墠鍐欓敊浜嗭紝涔熸病浜烘寚鍑猴紝鐪熸槸鍑勫噳
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