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Strings beginner

String.isBlank()

Check for blank strings with a single method call.

Code Comparison
✕ Java 8 
boolean blank =
    str.trim().isEmpty();
// or: str.trim().length() == 0
✓ Java 11+ 
boolean blank = str.isBlank();
// handles Unicode whitespace too
Why the modern way wins
📖

Self-documenting

isBlank() says exactly what it checks.

🌐

Unicode-aware

Handles all Unicode whitespace, not just ASCII.

⚡

No allocation

No intermediate trimmed string is created.

Old Approach
trim().isEmpty()
Modern Approach
isBlank()
Since JDK
11
Difficulty
beginner
JDK Support
String.isBlank()
Available

Widely available since JDK 11 (Sept 2018)

How it works

isBlank() returns true if the string is empty or contains only whitespace, including Unicode whitespace characters that trim() misses.

Related patterns

Strings beginner

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);
Hover to see modern ➜
JDK 15+ →
Strings beginner

String.strip() vs trim()

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();
Hover to see modern ➜
JDK 11+ →
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(" ", "-"));
Hover to see modern ➜
JDK 12+ →
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