---

id: 35

slug: "string-chars-stream"

title: "String chars as stream"

category: "strings"

difficulty: "beginner"

jdkVersion: "9"

oldLabel: "Java 8"

modernLabel: "Java 9+"

oldApproach: "Manual Loop"

modernApproach: "chars() Stream"

oldCode: |-

for (int i = 0; i < str.length(); i++) {

char c = str.charAt(i);

if (Character.isDigit(c)) {

process(c);

}

}

modernCode: |-

str.chars()

.filter(Character::isDigit)

.forEach(c -> process((char) c));

summary: "Process string characters as a stream pipeline."

explanation: "String.chars() returns an IntStream of character values, enabling functional\

\ processing. For Unicode support, codePoints() handles supplementary characters\

\ correctly."

whyModernWins:

- icon: "🔗"

title: "Chainable"

desc: "Use filter, map, collect on character streams."

- icon: "📐"

title: "Declarative"

desc: "Describe what to do, not how to loop."

- icon: "🌐"

title: "Unicode-ready"

desc: "codePoints() correctly handles emoji and supplementary chars."

support:

state: "available"

description: "Available since JDK 8+ (improved in 9+)"

prev: "strings/string-formatted"

next: "strings/string-lines"

related:

- "strings/string-repeat"

- "strings/string-isblank"

- "strings/string-formatted"

docs:

- title: "String.chars()"

href: "https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/String.html#chars()"

- title: "CharSequence.codePoints()"

href: "https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/CharSequence.html#codePoints()"