How to use string.startsWith()
method ignoring the case?
Case-insensitive comparison using toLowerCase()
on both strings before startsWith()
:
This transforms both str
and prefix
to lower case, effectively bypassing the case sensitivity.
Bypass case-sensitivity with regionMatches()
regionMatches()
offers an out-of-the-box solution for comparing specific regions of strings in a case-insensitive way:
The first parameter (ignoreCase
) specifies case-insensitive comparison.
Prefix magic with regex
Regular expressions provide powerful tools for pattern matching. We can easily perform a case-insensitive prefix check:
The Pattern.quote()
ensures special characters behave normally during string encounters.
Good guy Apache Commons Lang
Apache Commons Lang library saves the day with StringUtils.startsWithIgnoreCase()
. Offers a straightforward approach:
To utilize this, you have to include Apache Commons Lang in your project dependencies.
Embracing Unicode and locales
You might encounter Unicode strings, toLowerCase(Locale.ENGLISH)
ensures case conversions are accurate:
Locale-sensitive methods are saviours when characters escape the ASCII range.
Watch out for pitfalls
Converting the entire string to lower or upper case for comparisons can lead to performance overhead with large strings.
Even Java needs to take a breather sometimes, you might want to consider using regionMatches()
or StringUtils.startsWithIgnoreCase()
instead.
Checking against multiple prefixes
If you need to compare a string with multiple prefixes, use the Java 8 Stream for a swell and scalable solution:
This method completely disregards the case while checking for prefixes.
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