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Strings Beginner

String.strip() vs trim()

Use Unicode-aware stripping with strip(), stripLeading(), stripTrailing().

Strings

Code Comparison

✕ Java 8

// trim() only removes ASCII whitespace
// (chars <= U+0020)
String clean = str.trim();

✓ Java 11+

// strip() removes all Unicode whitespace
String clean = str.strip();
String left  = str.stripLeading();
String right = str.stripTrailing();

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Why the modern way wins

🌐

Unicode-correct

Handles all whitespace characters from every script.

🎯

Directional

stripLeading() and stripTrailing() for one-sided trimming.

🛡️

Fewer bugs

No surprise whitespace left behind in international text.

Old Approach

trim()

Modern Approach

strip()

Since JDK

Difficulty

Beginner

JDK Support

String.strip() vs trim()

Available

Widely available since JDK 11 (Sept 2018)

How it works

trim() only removes characters ≤ U+0020 (ASCII control chars and space). strip() uses Character.isWhitespace() which handles Unicode spaces like non-breaking space, ideographic space, etc.

String.formatted()

Java 8

String msg = String.format(
    "Hello %s, you are %d",
    name, age
);

Java 15+

String msg =
    "Hello %s, you are %d"
    .formatted(name, age);

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JDK 15+ →

Strings Beginner

String.indent() and transform()

Java 8

String[] lines = text.split("\n");
StringBuilder sb = new StringBuilder();
for (String line : lines) {
    sb.append("    ").append(line)
      .append("\n");
}
String indented = sb.toString();

Java 12+

String indented = text.indent(4);

String result = text
    .transform(String::strip)
    .transform(s -> s.replace(" ", "-"));

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JDK 12+ →

Strings Beginner

String chars as stream

Java 8

for (int i = 0; i < str.length(); i++) {
    char c = str.charAt(i);
    if (Character.isDigit(c)) {
        process(c);
    }
}

Java 9+

str.chars()
    .filter(Character::isDigit)
    .forEach(c -> process((char) c));

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JDK 9+ →