In kotlin source code, I can't understand how to implement of length of String.kt , it is as following:
package kotlin
public class String : Comparable<String>, CharSequence {
companion object {}
/**
* Returns a string obtained by concatenating this string with the string representation of the given [other] object.
*/
public operator fun plus(other: Any?): String
public override val length: Int
public override fun get(index: Int): Char
public override fun subSequence(startIndex: Int, endIndex: Int): CharSequence
public override fun compareTo(other: String): Int}
var len:Int = "abc".length; // len = 3 where to run the length??
where to implement the length function?
The string functions are examples of what Kotlin considers Intrinsic
functions. They are defined based on the platform they are running on and you won't be able to find an implementation of them in the source code.
For the JVM they will be directly mapped to the corresponding native java.lang.String
methods. This ensures there is no runtime overhead and leverages the optimizations done in the java standard library.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.