diff --git a/jiyeeeah/[week1]Array/array_length.js b/jiyeeeah/[week1]Array/array_length.js
new file mode 100644
index 0000000..57a454f
--- /dev/null
+++ b/jiyeeeah/[week1]Array/array_length.js
@@ -0,0 +1,7 @@
+function solution(strlist) {
+  const answer = [];
+  for (const str of strlist) {
+    answer.push(str.length);
+  }
+  return answer;
+}
diff --git a/jiyeeeah/[week1]Array/divided_number_array.js b/jiyeeeah/[week1]Array/divided_number_array.js
new file mode 100644
index 0000000..53458dd
--- /dev/null
+++ b/jiyeeeah/[week1]Array/divided_number_array.js
@@ -0,0 +1,9 @@
+function solution(arr, divisor) {
+  const answer = [];
+  for (const val of arr) {
+    if (val % divisor === 0) answer.push(val);
+  }
+  if (answer.length <= 0) answer.push(-1);
+  answer.sort((a, b) => a - b);
+  return answer;
+}
diff --git a/jiyeeeah/[week1]Array/number_of_duplicate.js b/jiyeeeah/[week1]Array/number_of_duplicate.js
new file mode 100644
index 0000000..9468c77
--- /dev/null
+++ b/jiyeeeah/[week1]Array/number_of_duplicate.js
@@ -0,0 +1,3 @@
+function solution(array, n) {
+  return array.filter((value) => value === n).length;
+}
diff --git a/jiyeeeah/[week1]Array/procession_multiply.js b/jiyeeeah/[week1]Array/procession_multiply.js
new file mode 100644
index 0000000..80033b2
--- /dev/null
+++ b/jiyeeeah/[week1]Array/procession_multiply.js
@@ -0,0 +1,18 @@
+function solution(arr1, arr2) {
+  const r1 = arr1.length;
+  const c1 = arr1[0].length;
+  const r2 = arr2.length;
+  const c2 = arr2[0].length;
+  // c1 === r2임
+
+  const answer = new Array(r1).fill(0).map(() => new Array(c2).fill(0));
+
+  for (let i = 0; i < r1; i++) {
+    for (let j = 0; j < c2; j++) {
+      for (let k = 0; k < c1; k++) {
+        answer[i][j] += arr1[i][k] * arr2[k][j];
+      }
+    }
+  }
+  return answer;
+}
diff --git a/jiyeeeah/[week1]Array/procession_sum.js b/jiyeeeah/[week1]Array/procession_sum.js
new file mode 100644
index 0000000..5c6f7db
--- /dev/null
+++ b/jiyeeeah/[week1]Array/procession_sum.js
@@ -0,0 +1,11 @@
+function solution(arr1, arr2) {
+  const Xn = arr1.length;
+  const Yn = arr1[0].length;
+  const answer = new Array(Xn).fill(0).map(() => new Array(Yn).fill(0));
+  for (let i = 0; i < Xn; i++) {
+    for (let j = 0; j < Yn; j++) {
+      answer[i][j] = arr1[i][j] + arr2[i][j];
+    }
+  }
+  return answer;
+}
diff --git a/jiyeeeah/[week1]Array/remove_min_number.js b/jiyeeeah/[week1]Array/remove_min_number.js
new file mode 100644
index 0000000..65b86a1
--- /dev/null
+++ b/jiyeeeah/[week1]Array/remove_min_number.js
@@ -0,0 +1,9 @@
+function solution(arr) {
+  const answer = [...arr];
+
+  const minNum = arr.sort((a, b) => a - b)[0];
+  answer.splice(answer.indexOf(minNum), 1);
+  if (answer.length <= 0) answer.push(-1);
+
+  return answer;
+}
diff --git a/jiyeeeah/[week1]Array/rotate_array.js b/jiyeeeah/[week1]Array/rotate_array.js
new file mode 100644
index 0000000..bc74102
--- /dev/null
+++ b/jiyeeeah/[week1]Array/rotate_array.js
@@ -0,0 +1,11 @@
+function solution(numbers, direction) {
+  const answer = [...numbers];
+  if (direction === "right") {
+    const temp = answer.pop();
+    answer.unshift(temp);
+  } else if (direction === "left") {
+    const temp = answer.shift();
+    answer.push(temp);
+  }
+  return answer;
+}
diff --git a/jiyeeeah/[week1]Array/trim_array.js b/jiyeeeah/[week1]Array/trim_array.js
new file mode 100644
index 0000000..95b02a0
--- /dev/null
+++ b/jiyeeeah/[week1]Array/trim_array.js
@@ -0,0 +1,4 @@
+function solution(numbers, num1, num2) {
+  const answer = numbers;
+  return answer.slice(num1, num2 + 1);
+}
diff --git "a/jiyeeeah/[week1]Array/\353\260\260\354\227\264.md" "b/jiyeeeah/[week1]Array/\353\260\260\354\227\264.md"
new file mode 100644
index 0000000..58bbf6c
--- /dev/null
+++ "b/jiyeeeah/[week1]Array/\353\260\260\354\227\264.md"
@@ -0,0 +1,24 @@
+> 이번에는 문제를 풀며 몰랐거나 까먹었다가 이제 다시 알게 된 부분들 위주로 정리해봤습니다.
+
+## 2차원 배열 만들기
+
+```js
+const arr = new Array(5).fill(0).map(() => new Array(4));
+```
+
+### 📄 REFERENCE
+
+https://joonfluence.tistory.com/508
+
+## 행렬의 곱셈
+
+```js
+const r1 = arr1.length;
+const c1 = arr1[0].length;
+const r2 = arr2.length;
+const c2 = arr2[0].length;
+// 여기서 c1 === r2이다.
+
+// 결과 배열은 r1 * c2이다.
+const answer = new Array(r1).fill(0).map(() => new Array(c2).fill(0));
+```