How to add items to Slice using append function in Golang?

To add an item to the end of the slice, use the append() method.


package main

import "fmt"

func main() {
	a := make([]int, 2, 5)
	a[0] = 10
	a[1] = 20
	fmt.Println("Slice A:", a)
	fmt.Printf("Length is %d Capacity is %d\n", len(a), cap(a))

	a = append(a, 30, 40, 50, 60, 70, 80, 90)
	fmt.Println("Slice A after appending data:", a)
	fmt.Printf("Length is %d Capacity is %d\n", len(a), cap(a))


Slice A: [10 20]
Length is 2 Capacity is 5
Slice A after appending data: [10 20 30 40 50 60 70 80 90]
Length is 9 Capacity is 12

If there's sufficient capacity in the underlying slice, the element is placed after the last element and the length get incremented. However, if there is not sufficient capacity, a new slice is created, all of the existing elements are copied over, the new element is added onto the end, and the new slice is returned.

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