【蓝桥杯Java_C组·从零开始卷】第二节(附)、if与switch效率比较(千万次/一亿次)下

package Action;
public class HelloWorld {
  static int count=10000000;
  public static void main(String[] args) {
    if_test();
    System.gc();
    switch_test();
  }
  public static void if_test() {
    long start = System.currentTimeMillis();
    for (int i = 0; i <count; i++) {
      if(i==(10000000-1)) {
        System.out.println("if判断一千万次");
      }else if(i==-1) {
      }else if(i==-2){
      }else if(i==-3){
      }else if(i==-4){
      }else if(i==-5){
      }else if(i==-6){
      }else if(i==-7){
      }else if(i==-8){
      }else if(i==-9){
      }else if(i==-10){
      }
    }
    long end = System.currentTimeMillis();
    System.out.println("if判断一千万次"+(end-start)+"毫秒");
  }
  public static void switch_test() {
    long start = System.currentTimeMillis();
    for (int i = 0; i <count; i++) {
      switch(i) {
        case 10000000-1:System.out.println("switch判断一千万次");break;
        case -1:break;
        case -2:break;
        case -3:break;
        case -4:break;
        case -5:break;
        case -6:break;
        case -7:break;
        case -8:break;
        case -9:break;
        case -10:break;
      }
    }
    long end = System.currentTimeMillis();
    System.out.println("switch判断一千万次"+(end-start)+"毫秒");
  }
}