diff --git a/docs/1-trial-session/08-loop/_samples/is-prime-using-and/script.js b/docs/1-trial-session/08-loop/_samples/is-prime-using-and/script.js
index f347ef983..8c7720e95 100644
--- a/docs/1-trial-session/08-loop/_samples/is-prime-using-and/script.js
+++ b/docs/1-trial-session/08-loop/_samples/is-prime-using-and/script.js
@@ -1,17 +1,17 @@
-const n = 89; //任意の整数
+const n = 89; // 任意の整数
 
 let isPrime = true;
 if (n <= 1) {
+  // nが1以下のときは素数でない
   isPrime = false;
 }
 
 for (let i = 2; i < n; i += 1) {
-  // nが1以下のときは素数でない
   isPrime = isPrime && n % i != 0;
 }
 
 if (isPrime) {
-  document.write(`${n} は素数です。`);
+  document.write(`${n} は素数です`);
 } else {
-  document.write(`${n} は素数ではありません。`);
+  document.write(`${n} は素数ではありません`);
 }
diff --git a/docs/1-trial-session/08-loop/_samples/is-prime/script.js b/docs/1-trial-session/08-loop/_samples/is-prime/script.js
index f3d73def7..9d55daed5 100644
--- a/docs/1-trial-session/08-loop/_samples/is-prime/script.js
+++ b/docs/1-trial-session/08-loop/_samples/is-prime/script.js
@@ -7,8 +7,8 @@ if (n <= 1) {
 }
 
 for (let i = 2; i < n; i += 1) {
-  if (n % i == 0) {
-    isPrime = false; // 変数には最後に代入した値のみを保持する
+  if (n % i === 0) {
+    isPrime = false;
   }
 }
 
diff --git a/docs/1-trial-session/08-loop/_samples/product-alt/script.js b/docs/1-trial-session/08-loop/_samples/product-alt/script.js
index ba2cec95a..a13270ea7 100644
--- a/docs/1-trial-session/08-loop/_samples/product-alt/script.js
+++ b/docs/1-trial-session/08-loop/_samples/product-alt/script.js
@@ -1,7 +1,5 @@
 let product = 1;
-
-for (let i = 1; i <= 10; i += 1){
+for (let i = 1; i <= 10; i += 1) {
   product *= i;
 }
-
 document.write(product);
diff --git a/docs/1-trial-session/08-loop/_samples/product/script.js b/docs/1-trial-session/08-loop/_samples/product/script.js
index 1f66ed4a5..67818e7a7 100644
--- a/docs/1-trial-session/08-loop/_samples/product/script.js
+++ b/docs/1-trial-session/08-loop/_samples/product/script.js
@@ -1,7 +1,5 @@
 let product = 1;
-
-for (i = 1; i <= 10; i = i + 1) {
+for (let i = 1; i <= 10; i = i + 1) {
   product = product * i;
 }
-
 document.write(product);
diff --git a/docs/1-trial-session/10-array/_samples/array-max/script.js b/docs/1-trial-session/10-array/_samples/array-max/script.js
index 26d913f31..b3fb6b817 100644
--- a/docs/1-trial-session/10-array/_samples/array-max/script.js
+++ b/docs/1-trial-session/10-array/_samples/array-max/script.js
@@ -1,3 +1,8 @@
+const array1 = [3, 6, 8, 5, 0];
+const array2 = [-8, -7, -3, -1, -5];
+const array3 = [5986, 7202, 9347, 3593, 8166, 662, 2235, 9323, 2240, 943];
+const array4 = [-878, -40, -324, -410, -592, -610, -880, -65, -423, -32];
+
 function findMaxNumber(numbers) {
   if (numbers.length === 0) return; // 空配列を除外
   let maxNumber = numbers[0];
@@ -9,11 +14,6 @@ function findMaxNumber(numbers) {
   return maxNumber;
 }
 
-const array1 = [3, 6, 8, 5, 0];
-const array2 = [-8, -7, -3, -1, -5];
-const array3 = [5986, 7202, 9347, 3593, 8166, 662, 2235, 9323, 2240, 943];
-const array4 = [-878, -40, -324, -410, -592, -610, -880, -65, -423, -32];
-
 document.write(
   `<p>配列 [${array1}] の最大値は${findMaxNumber(array1)} です。</p>`,
 );