计算每个单词在字符串中出现的次数
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
boolean b;
String s;
do {
System.out.println("请输入一句英语");
s=input.next();
String regex="[a-zA-Z ]*";
b=s.matches(regex);
} while (!b);
Character[] c=new Character[s.length()];
for (int i = 0; i <s.length() ; i++) {
c[i]=s.charAt(i);
}
Set<Character> set=new HashSet<>();
for (int i = 0; i < c.length; i++) {
set.add(c[i]);
}
StringBuffer str=new StringBuffer();
Iterator<Character> it=set.iterator();
while (it.hasNext()){
str.append(it.next());
}
Character[] c2=new Character[str.length()];
for (int i = 0; i <str.length() ; i++) {
c2[i]=str.charAt(i);
}
HashMap<Character,Integer> hashMap=new HashMap<>();
for (int i = 0; i < c2.length; i++) {
Integer count=0;
for (int j = 0; j < c.length; j++) {
if(c2[i].equals(c[j])){
count++;
}
}
hashMap.put(c2[i],count);
}
for (Map.Entry<Character, Integer> entry : hashMap.entrySet()) {
System.out.println(entry);
}
}
}
统计某个单词在字符串中出现的次数
public static void main(String[] args){
Scanner scanner=new Scanner(System.in);
System.out.println("输入字符串");
String srcText =scanner.next();
System.out.println("输入要查找的单词");
String findText = scanner.next();
int num = appearNumber(srcText, findText);
System.out.println("出现了"+num+"次");
}
public static int appearNumber(String srcText, String findText) {
int count = 0;
Pattern p = Pattern.compile(findText);
Matcher m = p.matcher(srcText);
while (m.find()) {
count++;
}
return count;
}
}