Java reference

String.startsWith()

Checks whether a string starts with the given prefix.

Available since: Java 1.0

Syntax

public boolean startsWith(String prefix)

Parameters

Parameter	Type	Description
prefix	String	The expected beginning of the string.

Return value

booleantrue if the string starts with prefix.

Examples

Checking the beginning of a string:

void main() {
    String url = "https://example.com";
    IO.println(url.startsWith("https://"));
    IO.println(url.startsWith("http://"));
}

Output:

true
false

Picking lines by a prefix:

void main() {
    String[] lines = {"# title", "text", "# note"};
    for (String line : lines) {
        if (line.startsWith("#")) {
            IO.println(line);
        }
    }
}

Output:

# title
# note

Notes

The check is case-sensitive. There is a version with an offset: startsWith("lo", 3) checks the text starting at index 3.

Related recipes

In the tutorial

String methods — The main String methods in Java: searching, substring, changing case, strip, replace, split, join, repeat and string checks.

Thanks for reading!