求解答按照视频巧的试过标点

package com.csdn;

import java.lang.reflect.Array;

public class DEMO6 {
static void testElse2() {
int a = 10;
if(a==20) {
System.out.println("20");
}else if (a==30);{
System.out.println("30");
}else if(a==40);{
System.out.println("40");
}else {
System.out.println("other");
}

}
static void testIfElse() {
    int i = 1;
    if (i>10) {
        System.out.println("大于10");
    }
    else {
        System.out.println("小于10");
    }
}

static void testIf() {
boolean flag = false;
if (flag) {
System.out.println("here");

  }
  System.out.println("end...");

}
public static void main (String[] args) {
testElse2();
// testIfElse();
// testIf();
}
}

Exception in thread "main" java.lang.Error: Unresolved compilation problems:
Syntax error on token "else", delete this token
Syntax error on token "else", delete this token

要删除else if后面的分号

}else if (a==30);{
System.out.println("30");
}else if(a==40);{
改为

}else if (a==30){
System.out.println("30");
}else if(a==40){