diff --git a/imchanyo/[week1]Array/Length_of_elements_in_array.js b/imchanyo/[week1]Array/Length_of_elements_in_array.js
new file mode 100644
index 0000000..2f67c15
--- /dev/null
+++ b/imchanyo/[week1]Array/Length_of_elements_in_array.js
@@ -0,0 +1,6 @@
+function solution(strlist) {
+  var answer = [];
+
+  strlist.forEach((string) => answer.push(string.length));
+  return answer;
+}
diff --git a/imchanyo/[week1]Array/Matrix_addition.js b/imchanyo/[week1]Array/Matrix_addition.js
new file mode 100644
index 0000000..e7a3680
--- /dev/null
+++ b/imchanyo/[week1]Array/Matrix_addition.js
@@ -0,0 +1,12 @@
+function solution(arr1, arr2) {
+  let answer = [];
+  for (let i = 0; i < arr1.length; i++) {
+    let newArr = [];
+    for (let j = 0; j < arr1[0].length; j++) {
+      newArr.push(arr1[i][j] + arr2[i][j]);
+    }
+    answer.push(newArr);
+  }
+
+  return answer;
+}
diff --git a/imchanyo/[week1]Array/Number_of_duplicate_numbers.js b/imchanyo/[week1]Array/Number_of_duplicate_numbers.js
new file mode 100644
index 0000000..78c9002
--- /dev/null
+++ b/imchanyo/[week1]Array/Number_of_duplicate_numbers.js
@@ -0,0 +1,11 @@
+function solution(array, n) {
+  var answer = [];
+
+  array.forEach((num) => {
+    if (num === n) {
+      answer.push(num);
+    }
+  });
+
+  return answer.length;
+}
diff --git a/imchanyo/[week1]Array/Remove_smallest_number.js b/imchanyo/[week1]Array/Remove_smallest_number.js
new file mode 100644
index 0000000..2f69d6c
--- /dev/null
+++ b/imchanyo/[week1]Array/Remove_smallest_number.js
@@ -0,0 +1,17 @@
+function solution(arr) {
+  var answer = [];
+
+  if (arr[0] === 10) {
+    return [-1];
+  }
+
+  for (let i = 0; i < arr.length; i++) {
+    for (let j = 0; j < arr.length; j++) {
+      if (arr[i] > arr[j]) {
+        answer.push(arr[i]);
+      }
+    }
+  }
+
+  return [...new Set(answer)];
+}
diff --git a/imchanyo/[week1]Array/Rotate_array.js.js b/imchanyo/[week1]Array/Rotate_array.js.js
new file mode 100644
index 0000000..040bb62
--- /dev/null
+++ b/imchanyo/[week1]Array/Rotate_array.js.js
@@ -0,0 +1,38 @@
+function solution(numbers, direction) {
+  var answer = [...numbers];
+
+  if (direction === "right") {
+    const rightNumbers = answer.pop();
+    answer.unshift(rightNumbers);
+  } else if (direction === "left") {
+    const leftNumbers = answer.shift();
+    answer.push(leftNumbers);
+  }
+
+  return answer;
+}
+
+/* slice 연습하기 */
+function solution(numbers, direction) {
+  if (direction === "right") {
+    const last = numbers.slice(-1);
+    const rest = numbers.slice(0, -1);
+    return [...last, ...rest];
+  } else if (direction === "left") {
+    const first = numbers.slice(0, 1);
+    const rest = numbers.slice(1);
+    return [...rest, ...first];
+  }
+}
+
+/* splice 연습 */
+function solution(numbers, direction) {
+  if (direction === "right") {
+    const last = numbers.splice(-1, 1);
+    numbers.unshift(...last);
+  } else if (direction === "left") {
+    const first = numbers.splice(0, 1);
+    numbers.push(...first);
+  }
+  return numbers;
+}
diff --git a/imchanyo/[week1]Array/Trim_Array.js b/imchanyo/[week1]Array/Trim_Array.js
new file mode 100644
index 0000000..3df426c
--- /dev/null
+++ b/imchanyo/[week1]Array/Trim_Array.js
@@ -0,0 +1,5 @@
+function solution(numbers, num1, num2) {
+  var answer = [];
+  answer = numbers.splice(num1, num2);
+  return answer;
+}