s1 := a[3:7]   // underlying array of s1 is array a; &s1[2] == &a[5]
s2 := s1[1:4]  // underlying array of s2 is underlying array of s1 which is array a; &s2[1] == &a[5]
s2[1] = 42     // s2[1] == s1[2] == a[5] == 42; they all refer to the same underlying array element

var s []int
s3 := s[:0]    // s3 == nil
</pre>


<h4>Full slice expressions</h4>

<p>

* API fields that previously serialized null arrays as `null` and empty arrays as `[]` no longer distinguish between those values and always output `[]` when serializing to JSON. ([#43422](https://github.com/kubernetes/kubernetes/pull/43422), [@liggitt](https://github.com/liggitt))

- EndpointSliceNodeName will always be enabled, so NodeName will always be available in the v1beta1 API. ([#99746](https://github.com/kubernetes/kubernetes/pull/99746), [@swetharepakula](https://github.com/swetharepakula)) [SIG Apps and Network]

  * Strategic Merge Patch

    * Reference docs now display the patch type and patch merge key used by `kubectl apply` to merge and identify unique elements in arrays.

      * `kubectl edit` and `kubectl apply` will keep the ordering of elements in merged lists ([#45980](https://github.com/kubernetes/kubernetes/pull/45980), [@mengqiy](https://github.com/mengqiy))

- resource.k8s.io/ResourceClaim (alpha API): The strategic merge patch strategy for the `status.reservedFor` array was changed so that a strategic-merge-patch can now add individual entries. This change may break clients using strategic merge patch to update status, which rely on the previous behavior (replacing the entire array).
   ([#122276](https://github.com/kubernetes/kubernetes/pull/122276), [@pohly](https://github.com/pohly))

- Removed the `CronJobTimeZone` feature gate (the feature is stable and always enabled)
  - Removed the `JobMutableNodeSchedulingDirectives` feature gate (the feature is stable and always enabled)

- Dynamic Resource Allocation (DRA): in the `pod.spec.recourceClaims` array, the `source` indirection is no longer necessary. Instead of e.g. `source: resourceClaimTemplateName: my-template`, one can write `resourceClaimTemplateName: my-template`. ([#125116](https://github.com/kubernetes/kubernetes/pull/125116), [@pohly](...

- CRDs can have fields named `type` with value `array` and nested array with `items` fields without validation to fall over this. ([#85223](https://github.com/kubernetes/kubernetes/pull/85223), [@sttts](https://github.com/sttts))

### Apps

* Scheduling conformance tests related to daemonsets should set the annotation that relaxes node selection restrictions, if any are set. This ensures conformance tests can run on a wider array of clusters. ([#68793](https://github.com/kubernetes/kubernetes/pull/68793), [@aveshaga...

- Added support for in-place vertical scaling of Pods with sidecars (containers defined within `initContainers` where the `restartPolicy` is set to `Always`). ([#128367](https://github.com/kubernetes/kubernetes/pull/128367), [@vivzbansal](https://github.com/vivzbansal)) [SIG API Machinery, Apps, CLI, Node, Scheduling and Testing]