1、字符串轉(zhuǎn)化（壓縮）“aabbccdaa”->“a2b2c2d1a2”
函數(shù)原型：
public static String stringCompress(String str){}思路：首先把原字符串由String類型轉(zhuǎn)換為StringBuilder類型，
然后再調(diào)用StringBuilder類里面的一些方法將原字符串進(jìn)行變換，
最后再返回String類型。
public?class?TestDemo1??{????public?static?String?stringCompress(String?str)?{????????StringBuilder?p?=?new?StringBuilder();????????p.append(str);????????p.replace(1,2,"2");????????p.replace(3,4,"2");????????p.replace(5,6,"2");????????p.insert(7,"1");????????p.replace(9,10,"2");????????return?p.toString();????}????public?static?void?main(String[]?args)?{???????String?str?=?"aabbccdaa";????????System.out.println(stringCompress(str));????}}結(jié)果如下
2、統(tǒng)計(jì)字符串中數(shù)字個(gè)數(shù)
//如：“abc21b416u”===>輸出5函數(shù)原型：public static int isNumeric(String str){}思路：首先通過String類里面的charAt()方法字符串中每個(gè)位置的字符，
然后通過Character.isDigit()方法來判斷得到的字符是否為數(shù)字并計(jì)數(shù)。
public?class?TestDemo1??{????public?static?int?isNumeric(String?str){????????int?count?=?0;????????for?(int?i?=?0;?i?<?str.length();?i++)?{????????????if?(Character.isDigit(str.charAt(i)))?{????????????????count++;????????????}????????}????????return?count;????}????public?static?void?main(String[]?args)?{???????String?str2?=?"abc21b416u";????????System.out.println(isNumeric(str2));????}}結(jié)果如下
3、題目：=====i am biter逆置為：biter am i
函數(shù)原型：
public static String reverseSentence(String str){}思路：（這個(gè)方法感覺都能把自己給蠢哭）先把原字符串分成三部分，
根據(jù)所想得到的結(jié)果，反復(fù)的使用reverse(）方法進(jìn)行反轉(zhuǎn)。
（其中還需要不斷的在String類和StringBuilder類之間進(jìn)行類型切換）
public?class?TestDemo1??{????public?static?String?reverseSentence(String?str)?{????????String?str1?=?str.substring(0,2);????????String?str2?=?str.substring(2,4);????????String?str3?=?str.substring(5);????????StringBuilder?p?=?new?StringBuilder();????????StringBuilder?q?=?new?StringBuilder();????????p.append(str2);????????q.append(str3);????????StringBuilder?x?=?p.reverse();????????StringBuilder?y?=?q.reverse();????????String?str4?=?x.toString();????????String?str5?=?y.toString();????????String?str6?=?str1?+?str4?+?"?"?+str5;????????StringBuilder?r?=?new?StringBuilder();????????r.append(str6);????????return?r.reverse().toString();????}????public?static?void?main(String[]?args)?{???????String?str?=?"i?am?biter";????????System.out.println(reverseSentence(str));????}}結(jié)果如下
以上就是長沙達(dá)內(nèi)教育java培訓(xùn)機(jī)構(gòu)的小編針對(duì)“這些初級(jí)的Java字符串練習(xí)題，你會(huì)做嗎”的內(nèi)容進(jìn)行的回答，希望對(duì)大家有所幫助，如有疑問，請?jiān)诰€咨詢，有專業(yè)老師隨時(shí)為你服務(wù)。
