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reflect.Len() Function in Golang with Examples

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Go language provides inbuilt support implementation of run-time reflection and allowing a program to manipulate objects with arbitrary types with the help of reflect package. The reflect.Len() Function in Golang is used to get the v’s length. To access this function, one needs to imports the reflect package in the program.

Syntax:

func (v Value) Len() int

Parameters: This function does not accept any parameter.

Return Value: This function returns v’s length

Below examples illustrate the use of the above method in Golang:

Example 1:




// Golang program to illustrate 
// reflect.Len() Function 
   
package main
    
 import (
    "fmt"
    "reflect"
 )
    
func main() {
    c := make(chan int, 1)
    vc := reflect.ValueOf(c)
       
    succeeded := vc.TrySend(reflect.ValueOf(123))
       
    // use of Len() method
    fmt.Println(succeeded, vc.Len(), vc.Cap())
    


Output:

true 1 1

Example 2:




// Golang program to illustrate 
// reflect.Len() Function 
    
package main 
     
import ( 
    "fmt"
    "reflect"
     
func main() {
    data := []string{"Geeks1", "Geeks2", "Geeks3"}
    test(data)
    data1 := []int{1, 2, 3}
    test(data1)
}
   
func test(t interface{}) {
    switch reflect.TypeOf(t).Kind() {
    case reflect.Slice:
        s := reflect.ValueOf(t)
           
        for i := 0; i < s.Len(); i++ {
            fmt.Println(s.Index(i))
        }
    }
}


Output:

Geeks1
Geeks2
Geeks3
1
2
3


Last Updated : 03 May, 2020
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