拆分段落Java:我想在一个变量中的前50个字从字符串

Question

我有过

String explanation = "The image-search feature will start rolling out in the next few days, said Johanna Wright, a Google search director. "Every picture has a story, and we want to help you discover that story she said.";

总字数是300

在Java中，如何从字符串中获取前50个单词？

Answer 1

给你，完美的解释：http://www.aliaspooryorik.com/blog/index.cfm/e/posts.details/post/show-the-first-n-and-last-n-words-232

Answer 2

根据您对单词的定义，这可能适用于您：

搜索第50个空格字符，然后提取从0到索引的子字符串。

下面是一些示例代码：

public static int nthOccurrence(String str, char c, int n) {
    int pos = str.indexOf(c, 0);
    while (n-- > 0 && pos != -1)
        pos = str.indexOf(c, pos+1);
    return pos;
}


public static void main(String[] args) {
    String text = "Lorem ipsum dolor sit amet.";

    int numWords = 4;
    int i = nthOccurrence(text, ' ', numWords - 1);
    String intro = i == -1 ? text : text.substring(0, i);

    System.out.println(intro); // prints "Lorem ipsum dolor sit"
}

相关问题：

• How to find nth occurrence of character in a string?

Answer 3

使用正则表达式拆分传入数据，进行边界检查，然后重新构建前50个单词。

String[] words = data.split(" ");
String firstFifty = "";
int max = words.length;
if (max > 50) 
  max = 50;
for (int i = 0; i < max; ++i)
  firstFifty += words[i] + " ";