public class StringBufferDemo02 {
public static void main(String[] args) {
StringBuffer bf = new StringBuffer("I am bf,");
// bf="I am a bf,";
fun1(bf);
String str = "I am str,";
fun2(str);
String str1 = fun3(str);
System.out.println(bf);
System.out.println(str);
System.out.println(str1);
}
public static void fun1(StringBuffer sb) {
sb.append(" has changed!");
}
public static void fun2(String str) {
str += " HAS CHANGED!";
}
public static String fun3(String str) {
str += " has changeeeeeeed!";
return str;
}
}
Output:
I am bf, has changed!
I am str,
I am str, has changeeeeeeed!
public class RunTimeDemo {
public static void main(String[] args) {
Runtime runtime = Runtime.getRuntime();
System.out.println("JVM'S MAX MEMORY:" + runtime.maxMemory());
System.out.println("JVM'S FREE MEMORY:" + runtime.freeMemory());
String string = "Hello" + "wORLD" + "!!!" + " " + "wellcomde" + "tO"
+ "VON" + "~~";
System.out.println(string);
for (int x = 0; x < 1000; x++) {
string += x;
}
System.out.println("After String's operate,JVM'S FREE MEMORY:"
+ runtime.freeMemory());
runtime.gc();
System.out.println("After Garbage collection,JVM'S FREE MEMORY:"
+ runtime.freeMemory());
}
}