goLogic errorMedium

Unexpected behavior when appending to a Go slice

Time: 0:00

BugFind the bug and fix the code

What it should do

Append a new element to the slice and return the updated slice. Example: appendSlice([1, 2], 3) -> [1, 2, 3]

What happens instead

The function does not append the new element to the slice as expected.

package main 

import "fmt"

func appendSlice(slice []int, element int) []int {
    newSlice := slice[:cap(slice)]
    newSlice = append(newSlice, element)
    return newSlice
}

func main() {
    slice := []int{1, 2}
    fmt.Println(appendSlice(slice, 3))
}

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

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Hints

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Hint 3

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This bug belongs to the logic errors pattern

The wrong operator, an inverted condition, a formula the right way round but backwards.

Learn the logic errors pattern Step through your own code

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package main import "fmt" func appendSlice(slice []int, element int) []int { newSlice := slice[:cap(slice)] newSlice = append(newSlice, element) return newSlice } func main() { slice := []int{1, 2} fmt.Println(appendSlice(slice, 3)) }

Unexpected behavior when appending to a Go slice

What it should do

What happens instead

More logic errors to practise

Unexpected behavior when appending to a Go slice

What it should do

What happens instead

More logic errors to practise