Files
codeql/java/ql/src/Performance/ConcatenationInLoops.java
2018-08-30 10:48:05 +01:00

18 lines
580 B
Java

public class ConcatenationInLoops {
public static void main(String[] args) {
Random r = new Random(123);
long start = System.currentTimeMillis();
String s = "";
for (int i = 0; i < 65536; i++)
s += r.nextInt(2);
System.out.println(System.currentTimeMillis() - start); // This prints roughly 4500.
r = new Random(123);
start = System.currentTimeMillis();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 65536; i++)
sb.append(r.nextInt(2));
s = sb.toString();
System.out.println(System.currentTimeMillis() - start); // This prints 5.
}
}