java如何才能让字符串数组中的字符随机输出一个 java怎么随机生成一个字符串？
java \u600e\u4e48\u968f\u673a\u6253\u5370\u81ea\u5b9a\u4e49\u6570\u7ec4\u91cc\u9762\u7684\u5b57\u7b26\u4e32\u4f60\u8981\u968f\u673a\u6253\u5370\u6570\u7ec4\u91cc\u9762\u7684\u4e1c\u897f\u5e72\u561b\u8981\u90a3\u4e48\u9ebb\u70e6\uff1f
int index1 = Arrays.binarySearch(arr, "\u732b");
int index2 = Arrays.binarySearch(arr, "\u72d7");
int index3 = Arrays.binarySearch(arr, "\u8001\u864e");
int index4 = Arrays.binarySearch(arr, "\u732a");
\u771f\u641e\u4e0d\u61c2\u4f60\u4e0a\u9762\u8fd9\u6bb5\u4ee3\u7801\u662f\u4ec0\u4e48\u610f\u601d\u3002\u6709\u610f\u4e49\u5417\u3002\u3002
\u4f60\u8981\u968f\u673a\u6253\u5370\u5c31\u968f\u673a\u751f\u6210\u6570\u7ec4\u4e0b\u6807\u5c31\u884c\u4e86\u554a\u3002
String [] arr=new String[]{"\u732b","\u72d7","\u8001\u864e","\u732a"};
Random random = new Random();
int index = random.nextInt(arr.length);//\u8fd4\u56de\u4e00\u4e2a\u4f2a\u968f\u673a\u6570\uff0c\u5b83\u662f\u53d6\u81ea\u6b64\u968f\u673a\u6570\u751f\u6210\u5668\u5e8f\u5217\u7684\u3001\u5728 0\uff08\u5305\u62ec\uff09\u548c\u6307\u5b9a\u503c\uff08\u4e0d\u5305\u62ec\uff09\u4e4b\u95f4\u5747\u5300\u5206\u5e03\u7684 int \u503c\u3002
System.out.println(arr[index]);//\u6253\u5370\u968f\u673a\u751f\u6210\u7684index\u4e0b\u6807\u6240\u6307\u5411\u7684\u90a3\u4e2a\u6570\u7ec4\u5143\u7d20\u3002
/**
* \u4ea7\u751f\u968f\u673a\u5b57\u7b26\u4e32
* */
private static Random randGen = null;
private static char[] numbersAndLetters = null;
public static final String randomString(int length) {
if (length < 1) {
return null;
}
if (randGen == null) {
randGen = new Random();
numbersAndLetters = ("0123456789abcdefghijklmnopqrstuvwxyz" +
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray();
//numbersAndLetters = ("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray();
}
char [] randBuffer = new char[length];
for (int i=0; i<randBuffer.length; i++) {
randBuffer[i] = numbersAndLetters[randGen.nextInt(71)];
//randBuffer[i] = numbersAndLetters[randGen.nextInt(35)];
}
return new String(randBuffer);
}
//\u8c03\u7528\u6b64\u65b9\u6cd5randomString(int),int\u662f\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\uff0c\u5373\u53ef\u4ea7\u751f\u6307\u5b9a\u957f\u5ea6\u7684\u968f\u673a\u5b57\u7b26\u4e32\u3002
1）用java.util.Random类：
Random rad = new Random();
int index = rad.nextInt(app.length);
System.out.println(app[index]);
2）用Math类：
int index = (int) Math.random() * app.length;
System.out.println(app[index]);
用随机数随机一个0到app.length-1的随机数r，输出app[r]
绛旓細java灏嗗瓧绗﹀瓨鍒版暟缁勪腑锛鍙互浣跨敤scanner绫绘帴鍙楃敤鎴蜂粠閿洏杈撳叆鐨勫瓧绗︼紝鐒跺悗閫氳繃for寰幆璇彞锛屾斁鍏ユ暟缁勪腑锛屽涓嬩唬鐮侊細import java.util.Scanner;public class c12{public static void main(String[] args){ Scanner s= new Scanner(System.in); System.out.println("璇疯緭鍏100涓瓧姣");//杈撳叆鐨勫瓧姣嶆暟閲 ...
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绛旓細1锛夌敤java.util.Random绫伙細Random rad = new Random();int index = rad.nextInt(app.length);System.out.println(app[index]);2锛夌敤Math绫伙細int index = (int) Math.random() * app.length;System.out.println(app[index]);
绛旓細1銆侀鍏堝彲浠ヤ娇鐢⊿tring[] s=new String[6]锛屽畾涔変竴涓暱搴︿负6鐨勫瓧绗︿覆鏁扮粍锛屽畾涔変箣鍚庯紝鍙互瀵瑰瓧绗︿覆鏁扮粍杩涜璧嬪锛屽涓嬪浘鎵绀恒2銆佷娇鐢╥nt[] i=new int[6]锛屽畾涔変竴涓暱搴︿负6鐨勬暣鍨嬫暟缁勶紝鍏跺畠绫诲瀷绫讳技锛屽涓嬪浘鎵绀恒3銆佷篃鍙互鍦ㄥ畾涔夋暟缁勭殑鏃跺欙紝鐩存帴瀵规暟缁勮繘琛岃祴鍊硷紝浣跨敤String[] str=new String[...
绛旓細int n = Integer.valueOf(input.nextLine().replaceAll("[^\\d]", ""));鏀规垚杩欐牱鍗冲彲;鍥犱负浣犵殑杈撳叆鍑芥暟,浣犱箣鍓嶈皟鐢ㄧ殑瀹僫nt绫诲瀷鏂规硶;鏀规垚杩欐牱,灏辩被浼间綘涓鐩寸敤鐨勯兘鏄瀛楃涓,鍖哄埆浣犵涓娆＄殑瀛楃涓茶Integer瀵硅薄杞垚鏁板瓧浜;
绛旓細public static void main(String[] args) { Scanner scan = null;try { scan = new Scanner(System.in);System.out.print( "璇疯緭鍏ヤ釜鏁: " );int inputNum = scan.nextInt();if( inputNum <= 0 ) { throw new Exception( "杈撳叆鏈夎" );} System.out.println( "璇疯緭鍏ユ暟瀛: " );...
绛旓細浣犺鍦╢or寰幆涔嬪new涓涓StringbBuffer鐨勫璞°傚湪for寰幆閲岄潰鍐嶇敤append鎷兼帴鎵琛屻備綘鐜板湪杩欎釜浠ｇ爜鏄瘡涓涓猚har閮絥ew鎴愪竴涓柊鐨凷tringBuffer瀵硅薄锛屼絾鏄洜涓轰綘姣忔new鐨勬椂鍊欓兘鏄敤鍚屼竴涓彉閲忔帴鏀剁殑锛屾墍浠ュ鑷翠綘鍦╢or瀹屾垚涔嬪悗涔熷彧鏈変竴涓猄tringBuffer瀵硅薄骞朵笖杩欎釜瀵硅薄瀛樼殑鏄綘鐨勬渶鍚庝竴涓狢har銆傝繖鏍疯緭鍑虹殑鑲畾...
绛旓細姣斿浣犱粠鎺у埗鍙拌繘琛岃鍙栨搷浣滐紝閭ｄ箞浣犲彲浠ヤ互绌烘牸浣滀负鍒嗛殧绗︽潵杩涜鍒嗗壊锛岀劧鍚庡瓨鍌ㄥ湪鏁扮粍涓锛屼緥瀛愶細import java.util.Scanner;public class Demo02 { public Demo02(){ Scanner in = new Scanner(System.in);System.out.println("璇疯緭鍏ワ紝渚嬪锛氫綘濂 鎴戞槸鏌愭煇 鎴戞槸鍦ㄦ牎瀛︾敓");String []str = in....
绛旓細鎽樿嚜API toCharArray public char[] toCharArray()灏姝ゅ瓧绗︿覆杞崲涓轰竴涓柊鐨瀛楃鏁扮粍銆傝繑鍥烇細涓涓柊鍒嗛厤鐨勫瓧绗︽暟缁勶紝瀹冪殑闀垮害鏄瀛楃涓茬殑闀垮害锛屽畠鐨勫唴瀹硅鍒濆鍖栦负鍖呭惈姝ゅ瓧绗︿覆琛ㄧず鐨勫瓧绗﹀簭鍒椼備緥濡傦細String aa = "121212";char[] ss = aa.toCharArray();...
绛旓細import java.util.*;public class Test1 { public static void main(String[] args){ System.out.println("Hello World!");HashSet hs = new HashSet();hs.add("abc");hs.add("abc");hs.add("hello world");for (Iterator it=hs.iterator();it.hasNext() ; ){ System.out.println(...
