Java indexOf 为未找到的字符串返回false？
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Java indexOf returns false for unfound string?
提问by Supernovah
I need to know whether in Java does the indexOf()method return falseor voidfor an unfound string? or does it return an index intof 0?
我需要知道在 Java 中该indexOf()方法是返回false还是返回void未找到的字符串？还是返回索引int为 0？
回答by Brian Agnew
回答by Thomas Owens
The Java API docscontain this answer. the indexOfmethods on a Stringreturn -1 if the character is not found.
在Java的API文档包含这个答案。如果未找到字符，则返回 -1的indexOf方法String。
回答by Gustavo
You mean Javascript? It returns -1.
你的意思是Javascript？它返回-1。
回答by Brian Rasmussen
回答by scunliffe
Only PHP's str_posis weird enough to return 0/false when the index isn't found. Most consider the PHP version to be a bad implementation.
只有PHP 的 str_pos很奇怪，当找不到索引时返回 0/false 。大多数人认为 PHP 版本是一个糟糕的实现。
int strpos ( string $haystack , mixed $needle [, int $offset= 0 ] )
//Returns the position as an integer. If needle is not found, strpos()
// will return boolean FALSE.
/*
Warning
function may return Boolean FALSE, but may also return a non-Boolean value which
evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more
information. Use the === operator for testing the return value of this function.
*/
