Java String Concatenation Performance: + vs StringBuilder
Java string concatenation performance on JDK 25 with JMH results, how + compiles since JEP 280, why += in loops is slow, and concat() vs StringBuilder.
Java Multiline String: Text Blocks and Older Options
Write a Java multiline string with text blocks, control indentation, line breaks and trailing spaces, and see the String.join() options for Java 8 to 14.
Align Text in Columns in Java: Print a Table with printf
Align text in columns in Java with printf widths, widths computed from the data, cut long values and a small TextTable class that prints Markdown tables.
Java String Templates: Withdrawn in JDK 23, What to Use Now
Java string templates were withdrawn in JDK 23 and do not exist in Java 25. See the old syntax, why it was dropped and the replacements that work today.
Java String & Regex Tutorials
Java String methods grouped by task with Java 25 examples, from equals() and compareTo() to strip(), split() and replaceAll(), with pitfalls and FAQs.
Remove Last Character from a String in Java (6 Ways)
How to remove last character from a string in Java with substring(), StringBuilder, regex and chop(), safe for null, empty strings and emoji.
Java String Constant Pool and intern() Explained
Learn how the Java string constant pool works, why it is in the heap since Java 7, how String.intern() behaves and when string deduplication saves memory.
Java String isBlank(): Check Blank or Empty String
Java String isBlank() checks if a string is empty or only whitespace. See isBlank() vs isEmpty() and trim(), null-safe checks, Unicode cases and FAQs.
Repeat a String N Times in Java: repeat() and Alternatives
Repeat a string N times in Java with String.repeat(), StringBuilder.repeat(), String.join() with nCopies, Java 8 loops and StringUtils, with edge cases.
Java Format Phone Number with Regex: (123) 456-7890
Java format phone number examples with regex groups and replaceFirst(), cleanup of typed input, a safe method with Optional, substring and E.164 storage.
Get First 4 Characters of a String in Java (Safe Ways)
Get first 4 characters of a string in Java with substring() and Math.min(), safe for short strings, null and emoji, plus previews with an ellipsis.
Get Last 4 Characters of a String in Java (Null-Safe)
Get last 4 characters of a string in Java with substring() and Math.max(), handling short strings, null, emoji and formatted phone numbers.
Java String split(): Limit, Regex Escaping and Empty Strings
Java String split() explained with the limit argument, escaping regex special characters, trailing empty strings and Java 21 splitWithDelimiters().
Java String startsWith(): Ignore Case, Offset, Multiple Prefixes
Java String startsWith() examples for single and multiple prefixes, the offset overload, ignoring case with regionMatches, regex prefixes and null safety.
Find Duplicate Characters in a String in Java (With Counts)
Find duplicate characters in a string in Java with a map, streams, an int array or sorting, plus case, emoji, first unique character and complexity.
Convert Float to String in Java with N Decimal Places
Convert float to String in Java with Float.toString(), String.format(“%.2f”) and DecimalFormat, plus locale, rounding, null and scientific notation.
Convert Exception Stack Trace to String in Java
Convert an exception stack trace to string in Java with StringWriter and PrintWriter, read causes and suppressed lines, and store or log it safely.
Right Pad a String in Java With Spaces, Zeros or Any Char
Right pad a string in Java with spaces, zeros or any character using String.format(), repeat(), StringUtils.rightPad() and Guava, plus truncation.
Left Pad a String with Spaces or Zeros in Java (5 Ways)
Left pad a string in Java with spaces or leading zeros using String.format(), repeat(), StringUtils.leftPad() and Guava, with negative numbers and nulls.
Java StringJoiner: Join Strings With a Delimiter and Prefix
Learn the Java StringJoiner class with add(), setEmptyValue(), merge() and length() examples, and compare it with String.join() and Collectors.joining().
Java Remove Extra Spaces Between Words in a String
Java remove extra spaces between words with replaceAll() and strip(), normalizeSpace(), split and join, plus non-breaking spaces and line breaks.
Java Remove Leading and Trailing Whitespace: trim() vs strip()
Java remove leading and trailing whitespace with strip(), stripLeading(), stripTrailing() and trim(), plus Unicode spaces, non-breaking spaces and null.
Convert int to String in Java (Integer.toString vs valueOf)
Convert int to String in Java with Integer.toString(), String.valueOf() and format(), plus null Integer, locale digits, hex and long to String.
Convert a String to Title Case in Java (With Examples)
Convert a string to title case in Java with Character.toTitleCase(), a regex, split() or WordUtils, and keep small words such as of and the lowercase.
Java Unescape HTML: Decode HTML Entities to a String
Java unescape HTML examples with Commons Text unescapeHtml4(), Spring HtmlUtils and jsoup, plus a plain Java method and a fix for double-escaped text.
Java Escape HTML: Encode Special Characters in a String
Java escape HTML examples with OWASP Java Encoder, Commons Text escapeHtml4() and Spring HtmlUtils, plus a plain Java method and how quotes differ.
Java String to int: parseInt(), valueOf() and Safe Parsing
Convert a Java String to int with Integer.parseInt() and valueOf(), handle NumberFormatException safely, and parse hex, big numbers, chars and input.
Comma-Separated String to List in Java (split and Streams)
Convert a comma-separated string to list in Java with split(), Arrays.asList(), List.of() and streams, handling spaces, empty values and numbers.
Join String Array in Java with Comma or Any Separator
Join String array in Java with String.join(), Collectors.joining() and StringJoiner, handle null and empty values, and join int arrays.
Left, Right or Center Align a String in Java (Examples)
Learn to align a string in Java to the left, right or center with String.format(), a repeat() helper for centering, StringUtils and word-wrapped text.
Split a String in Java: split(), Pattern, Scanner and More
Learn to split a string in Java with split(), Pattern, splitAsStream(), Java 21 splitWithDelimiters(), lines(), Scanner and StringTokenizer.
Why Strings Are Immutable in Java: Reasons and Examples
Learn why Strings are immutable in Java, how the final String class enforces it, and how the string pool, hash caching, threads and security depend on it.
Find Duplicate Words in a String in Java (Count and Remove)
Find duplicate words in a string in Java with Set, groupingBy() and merge(), ignore case and punctuation, find repeated words with regex and remove them.
