@@ -2,7 +2,7 @@
 
 // Use a 'for' loop
 function repeatStringNumTimesWithFor(str, num) {
-	const result = " ";
+	let result = " ";
 	for (let i = 0; num > i; i++) {
 		result += str;
 	}
@@ -14,7 +14,7 @@ console.log('for', repeatStringNumTimesWithFor('abc', 3));
 
 // Use a 'while' loop
 function repeatStringNumTimesWithWhile(str, num) {
-	const result = '';
+	let result = '';
 	while (num > 0) {
 		result += str;
 		num--;
@@ -26,7 +26,7 @@ console.log('while', repeatStringNumTimesWithWhile('abc', 3));
 
 // Use a 'do...while' loop
 function repeatStringNumTimesWithDoWhile(str, num) {
-	const result = '';
+	let result = '';
 	do {
 		result += str;
 		num--;
 
@@ -5,7 +5,7 @@ const arr3d = [[[1, 2], [3, 4]], [[5, 6], [7, 8]]];
 
 function flattenArray2d(arr) {
 	//	let arr2Flat = [].concat.apply([], arr2d);
-	let arr2Flat = arr2d.flat();
+	let arr2Flat = arr.flat();
 	return arr2Flat;
 }
Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,7 @@ const arr3d = [[[1, 2], [3, 4]], [[5, 6], [7, 8]]];`
`5`	`5`
`6`	`6`	`function flattenArray2d(arr) {`
`7`	`7`	`// let arr2Flat = [].concat.apply([], arr2d);`
`8`		`- let arr2Flat = arr2d.flat();`
	`8`	`+ let arr2Flat = arr.flat();`
`9`	`9`	`return arr2Flat;`
`10`	`10`	`}`
`11`	`11`