//構(gòu)建一個(gè)java程序，查找字符"a"在字符串"What happend today"中出現(xiàn)的次數(shù)。

package a;

public class Student{

public static void main(String[] args) {

? ?

String str="What happend today";

int times = searchstr("a", str); //返回2

System.out.println("字符a在字符串What happend today中出現(xiàn)的次數(shù):"+times); /*times就是次數(shù)的意思*/

}

public? static? int? ?searchstr(String key/*要搜索的關(guān)鍵詞*/, String str/*字符串*/) {

int index = 0;//每次的搜索到的下標(biāo)

int count = 0;//計(jì)數(shù)器

while (( index=str.indexOf(key, index)) != -1) {

index = index + key.length()/*關(guān)鍵詞的長度*/;

count++;

}

return count; /*沒void就要寫return，這是規(guī)定*/

? ? ? ??

? ? }

}