Question

我需要这段代码来搜索指定的字符串，当它找到一个输出时，然后继续寻找更多。

  int FoundPsn = sample.indexOf("quick", 0);
  System.out.print("sample.indexOf(\"quick\") = " + FoundPsn);

Answer 1

尝试类似的东西：

    String sample = "quick, that was quick, and maybe quicker!";
    int foundPsn = 0;
    int startSearch = 0;
    String search = "quick";
    while ((foundPsn = sample.indexOf(search, startSearch)) >= 0){
        System.out.println("sample.indexOf(\"quick\") = " + foundPsn);
        startSearch = foundPsn + search.length();
    }

Answer 2

工作方法指数：

Returns the index within this string of the first occurrence of the specified substring, starting at the specified index.
The returned index is the smallest value k for which:

 k >= fromIndex && this.startsWith(str, k)

如果不存在这样的k值，则返回-1。

Sourdes Java doc：https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#indexOf(java.lang.String,%20int)

你可以做的是保持循环，直到它达到-1之类。

int FoundPsn = sample.indexOf("quick");
while(FoundPsn != -1) {
    System.out.println("sample.indexOf(\"quick\") = " + FoundPsn);
    FoundPsn = sample.indexOf("quick", FoundPsn+1);
}

注意：如果您只搜索一个字符，并且恰好是最后一个字符，那么这将使索引超出范围。

如何为indexOf创建for循环（String str，int fromIndex）

2 个答案: