Question

java里如何判断一句话里单词的个数

"Thank you for applying for a job at Exo-web.It is our pleasure to
welcome you for an initial testand interview's as follows"

Answer 1

BreakIterator boundary = BreakIterator.getWordInstance();
boundary.setText(s);
int start = boundary.first();
int b = 0;
for (int end = boundary.next(); end != BreakIterator.DONE; start = end, end = boundary.next()){
String sub = s.substring(start, end);
if(sub.length()>1){
b++;
}else if(sub.length() == 1){
Pattern pattern = Pattern.compile("^[a-zA-Z]$");
Matcher matcher = pattern.matcher(sub);
if ( matcher.matches() ) {
b++;
}
}
}
System.out.println(b);

应该没啥大问题
如果数字也算的话，正则表达式改成^[a-zA-Z0-9]$
。。发现bug，句号不会分割。。
可以考虑先split('.')成为字符串数组在来用这个方法。

String[] array = str.split("\\.");
int b = 0;
for (String s : array) {
BreakIterator boundary = BreakIterator.getWordInstance();
boundary.setText(s);
int start = boundary.first();

for (int end = boundary.next(); end != BreakIterator.DONE; start = end, end = boundary.next()){
String sub = s.substring(start, end);
if(sub.length()>1){
b++;
System.out.println(sub);
}else if(sub.length() == 1){
Pattern pattern = Pattern.compile("^[a-zA-Z]$");
Matcher matcher = pattern.matcher(sub);
if ( matcher.matches() ) {
b++;
System.out.println(sub);
}
}
}
}

Answer 2

String.split(' ').length()

Answer 3

你可以通过判断句子中空格的个数来判断单词的个数。
另外注意一下，标点符号。