diff --git a/builtin/array_block.mbt b/builtin/array_block.mbt
index 70bb0532..09139dd5 100644
--- a/builtin/array_block.mbt
+++ b/builtin/array_block.mbt
@@ -19,7 +19,7 @@ pub fn Array::unsafe_blit[A](
   src_offset : Int,
   len : Int
 ) -> Unit {
-  FixedArray::unsafe_blit(dst.buf._, dst_offset, src.buf._, src_offset, len)
+  FixedArray::unsafe_blit(dst.buffer()._, dst_offset, src.buffer()._, src_offset, len)
 }
 
 pub fn Array::unsafe_blit_fixed[A](
@@ -30,7 +30,7 @@ pub fn Array::unsafe_blit_fixed[A](
   len : Int
 ) -> Unit {
   UninitializedArray::unsafe_blit_fixed(
-    dst.buf,
+    dst.buffer(),
     dst_offset,
     src,
     src_offset,
diff --git a/builtin/arraycore_js.mbt b/builtin/arraycore_js.mbt
new file mode 100644
index 00000000..a8bcd0c2
--- /dev/null
+++ b/builtin/arraycore_js.mbt
@@ -0,0 +1,268 @@
+// Copyright 2024 International Digital Economy Academy
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+priv type UninitializedArray[T] FixedArray[UnsafeMaybeUninit[T]]
+
+fn UninitializedArray::make[T](size : Int) -> UninitializedArray[T] = "%fixedarray.make_uninit"
+
+fn op_get[T](self : UninitializedArray[T], index : Int) -> T = "%fixedarray.get"
+
+fn op_set[T](self : UninitializedArray[T], index : Int, value : T) = "%fixedarray.set"
+
+fn set_null[T](self : UninitializedArray[T], index : Int) = "%fixedarray.set_null"
+
+fn UninitializedArray::unsafe_blit[T](
+  dst : UninitializedArray[T],
+  dst_offset : Int,
+  src : UninitializedArray[T],
+  src_offset : Int,
+  len : Int
+) -> Unit {
+  FixedArray::unsafe_blit(dst._, dst_offset, src._, src_offset, len)
+}
+
+/// @intrinsic %fixedarray.copy
+fn UninitializedArray::unsafe_blit_fixed[T](
+  dst : UninitializedArray[T],
+  dst_offset : Int,
+  src : FixedArray[T],
+  src_offset : Int,
+  len : Int
+) -> Unit {
+  for i = len - 1; i >= 0; i = i - 1 {
+    dst[dst_offset + i] = src[src_offset + i]
+  }
+}
+
+//#region
+// These type are of workaround for the restriction that MoonBit do not support 
+// generic type parameters of extern ffi 
+
+type JSValue
+
+fn JSValue::ofAny[T](array: T) -> JSValue  = "%identity"
+fn JSValue::toAny[T](self: JSValue) -> T = "%identity"
+
+type JSArray
+
+fn JSArray::ofAnyArray[T](array: Array[T]) -> JSArray  = "%identity"
+fn JSArray::toAnyArray[T](self: JSArray) -> Array[T] = "%identity"
+
+extern "js" fn JSArray::set_length(self: JSArray, new_len: Int) -> Unit = 
+#| (arr, len) => { arr.length = len; }
+
+extern "js" fn JSArray::push(self: JSArray, value: JSValue) -> Unit =
+#| (arr, val) => { arr.push(val); }
+
+extern "js" fn JSArray::pop(self: JSArray) -> JSValue =
+#| (arr) => arr.pop()
+
+extern "js" fn JSArray::splice(self: JSArray, index: Int, count: Int) -> JSArray =
+#| (arr, idx, cnt) => arr.splice(idx, cnt)
+
+extern "js" fn JSArray::splice1(self: JSArray, index: Int, count: Int, value: JSValue) -> JSArray =
+#| (arr, idx, cnt, val) => arr.splice(idx, cnt, val)
+
+//#endregion
+
+/// An `Array` is a collection of values that supports random access and can
+/// grow in size.
+type Array[T] FixedArray[T]
+
+fn Array::make_uninit[T](len : Int) -> Array[T] = "%fixedarray.make_uninit"
+
+/// Creates a new array.
+pub fn Array::new[T](~capacity : Int = 0) -> Array[T] {
+  []
+}
+
+/// Returns the number of elements in the array.
+pub fn length[T](self : Array[T]) -> Int = "%fixedarray.length"
+
+fn set_length[T](self : Array[T], new_len : Int) -> Unit {
+  JSArray::ofAnyArray(self).set_length(new_len) 
+}
+
+fn buffer[T](self : Array[T]) -> UninitializedArray[T] = "%identity"
+
+test "array_unsafe_blit_fixed" {
+  let src = FixedArray::make(5, 0)
+  let dst = UninitializedArray::make(5)
+  for i in 0..<5 {
+    src[i] = i + 1
+  }
+  UninitializedArray::unsafe_blit_fixed(dst, 0, src, 0, 5)
+  for i in 0..<5 {
+    assert_eq!(dst[i], src[i])
+  }
+}
+
+
+test "UninitializedArray::unsafe_blit_fixed" {
+  let src = FixedArray::make(5, 0)
+  let dst = UninitializedArray::make(5)
+  for i in 0..<5 {
+    src[i] = i + 1
+  }
+  UninitializedArray::unsafe_blit_fixed(dst, 0, src, 0, 5)
+  for i in 0..<5 {
+    assert_eq!(dst[i], src[i])
+  }
+}
+
+test "UninitializedArray::unsafe_blit_fixed" {
+  let src = FixedArray::make(5, 0)
+  let dst = UninitializedArray::make(5)
+  for i in 0..<5 {
+    src[i] = i + 1
+  }
+  UninitializedArray::unsafe_blit_fixed(dst, 0, src, 0, 5)
+  for i in 0..<5 {
+    assert_eq!(dst[i], src[i])
+  }
+}
+
+/// Reserves capacity to ensure that it can hold at least the number of elements
+/// specified by the `capacity` argument.
+/// 
+/// **NOTE**: This method does nothing on js platform.
+/// # Example
+///
+/// ```
+/// let v = [1]
+/// v.reserve_capacity(10)
+/// println(v.capacity()) // 10
+/// ```
+pub fn reserve_capacity[T](self : Array[T], capacity : Int) -> Unit {}
+
+/// Shrinks the capacity of the array as much as possible.
+///
+/// **NOTE**: This method does nothing on js platform.
+/// # Example
+///
+/// ```
+/// let v = Array::new(capacity=10)
+/// v.push(1)
+/// v.push(2)
+/// v.push(3)
+/// println(v.capacity()) // >= 10
+/// v.shrink_to_fit()
+/// println(v.capacity()) // >= 3
+/// ```
+pub fn shrink_to_fit[T](self : Array[T]) -> Unit {}
+
+/// Adds an element to the end of the array.
+///
+/// If the array is at capacity, it will be reallocated.
+///
+/// # Example
+/// ```
+/// let v = []
+/// v.push(3)
+/// ```
+pub fn push[T](self : Array[T], value : T) -> Unit {
+  JSArray::ofAnyArray(self).push(JSValue::ofAny(value))
+}
+
+/// Removes the last element from a array and returns it, or `None` if it is empty.
+///
+/// # Example
+/// ```
+/// let v = [1, 2, 3]
+/// v.pop()
+/// ```
+pub fn pop[T](self : Array[T]) -> T? {
+  if self.length() == 0 {
+    None
+  } else {
+    let v = self.unsafe_pop()
+    Some(v)
+  }
+}
+
+/// @alert deprecated "Use `unsafe_pop` instead"
+pub fn pop_exn[T](self : Array[T]) -> T {
+  self.unsafe_pop()
+}
+
+/// Removes the last element from a array and returns it.
+/// 
+/// **NOTE** This method won't panic but undefined behavior on js platform. Use at your own risk.
+/// @alert unsafe "Panic if the array is empty."
+pub fn unsafe_pop[T](self : Array[T]) -> T {
+  JSArray::ofAnyArray(self).pop().toAny()
+}
+
+/// Remove an element from the array at a given index.
+///
+/// Removes and returns the element at position index within the array, shifting all elements after it to the left.
+///
+/// # Example
+/// ```
+/// let v = [3, 4, 5]
+/// v.remove(1)
+/// ```
+/// @alert unsafe "Panic if index is out of bounds."
+pub fn remove[T](self : Array[T], index : Int) -> T {
+  if index < 0 || index >= self.length() {
+    let len = self.length()
+    abort(
+      "index out of bounds: the len is from 0 to \{len} but the index is \{index}",
+    )
+  }
+  let value = self.buffer()[index]
+  let _ = JSArray::ofAnyArray(self).splice(index, 1)
+  value
+}
+
+/// Removes the specified range from the array and returns it.
+///
+/// This functions returns a array range from `begin` to `end` `[begin, end)`
+///
+/// # Example
+/// ```
+/// let v = [3, 4, 5]
+/// let vv = v.drain(1, 2) // vv = [4], v = [3, 5]
+/// ```
+/// @alert unsafe "Panic if index is out of bounds."
+pub fn drain[T](self : Array[T], begin : Int, end : Int) -> Array[T] {
+  if begin < 0 ||
+    begin >= self.length() ||
+    end < 0 ||
+    end > self.length() ||
+    begin > end {
+    let len = self.length()
+    abort(
+      "index out of bounds: the len is \{len} but the index is (\{begin}, \{end})",
+    )
+  }
+  JSArray::ofAnyArray(self).splice(begin, end - begin).toAnyArray()
+}
+
+/// Inserts an element at a given index within the array.
+///
+/// # Example
+/// ```
+/// [3, 4, 5].insert(1, 6)
+/// ```
+/// @alert unsafe "Panic if index is out of bounds."
+pub fn insert[T](self : Array[T], index : Int, value : T) -> Unit {
+  if index < 0 || index > self.length() {
+    let len = self.length()
+    abort(
+      "index out of bounds: the len is from 0 to \{len} but the index is \{index}",
+    )
+  }
+  let _ = JSArray::ofAnyArray(self).splice1(index, 0, JSValue::ofAny(value))
+}
diff --git a/builtin/arraycore.mbt b/builtin/arraycore_nonjs.mbt
similarity index 100%
rename from builtin/arraycore.mbt
rename to builtin/arraycore_nonjs.mbt
diff --git a/builtin/moon.pkg.json b/builtin/moon.pkg.json
index 95838854..01b2ad22 100644
--- a/builtin/moon.pkg.json
+++ b/builtin/moon.pkg.json
@@ -15,6 +15,8 @@
   ],
   "targets": {
     "int64_js.mbt": ["js"],
-    "int64_nonjs.mbt": ["not", "js"]
+    "int64_nonjs.mbt": ["not", "js"],
+    "arraycore_js.mbt": ["js"],
+    "arraycore_nonjs.mbt": ["not", "js"]
   }
 }