kotlin中const 和val的区别及使用场景分析

val pi = 3.14  // 运行时计算
val name = "Kotlin"  // 运行时计算

const val LATEST_VERSION: Int = 4  // 编译时常量
const val PI: Double = 3.14159  // 编译时常量

package test.f
const val LATEST_VERSION: Int = 4  // 编译时常量
const val PI: Double = 3.14159  // 编译时常量
class Test4 {
    val pi = 3.14  // 运行时计算
    val name = "Kotlin"  // 运行时计算
}

// Test4.java
package test.f;
import kotlin.Metadata;
import org.jetbrains.annotations.NotNull;
@Metadata(
   mv = {2, 0, 0},
   k = 1,
   xi = 48,
   d1 = {"\u0000\u001c\n\u0002\u0018\u0002\n\u0002\u0010\u0000\n\u0002\b\u0002\n\u0002\u0010\u000e\n\u0002\b\u0003\n\u0002\u0010\u0006\n\u0002\b\u0003\u0018\u00002\u00020\u0001B\u0005¢\u0006\u0002\u0010\u0002R\u0014\u0010\u0003\u001a\u00020\u0004X\u0086D¢\u0006\b\n\u0000\u001a\u0004\b\u0005\u0010\u0006R\u0014\u0010\u0007\u001a\u00020\bX\u0086D¢\u0006\b\n\u0000\u001a\u0004\b\t\u0010\n¨\u0006\u000b"},
   d2 = {"Ltest/f/Test4;", "", "()V", "name", "", "getName", "()Ljava/lang/String;", "pi", "", "getPi", "()D", "untitled"}
)
public final class Test4 {
   private final double pi = 3.14;
   @NotNull
   private final String name = "Kotlin";
   public final double getPi() {
      return this.pi;
   }
   @NotNull
   public final String getName() {
      return this.name;
   }
}
// Test4Kt.java
package test.f;
import kotlin.Metadata;
@Metadata(
   mv = {2, 0, 0},
   k = 2,
   xi = 48,
   d1 = {"\u0000\u000e\n\u0000\n\u0002\u0010\b\n\u0000\n\u0002\u0010\u0006\n\u0000\"\u000e\u0010\u0000\u001a\u00020\u0001X\u0086T¢\u0006\u0002\n\u0000\"\u000e\u0010\u0002\u001a\u00020\u0003X\u0086T¢\u0006\u0002\n\u0000¨\u0006\u0004"},
   d2 = {"LATEST_VERSION", "", "PI", "", "untitled"}
)
public final class Test4Kt {
   public static final int LATEST_VERSION = 4;
   public static final double PI = 3.14159;
}