diff --git a/1-js/05-data-types/03-string/1-ucfirst/solution.md b/1-js/05-data-types/03-string/1-ucfirst/solution.md
@@ -1,19 +1,19 @@
-We can't "replace" the first character, because strings in JavaScript are immutable.

-But we can make a new string based on the existing one, with the uppercased first character:

```js
let newStr = str[0].toUpperCase() + str.slice(1);
```

-There's a small problem though. If `str` is empty, then `str[0]` is `undefined`, and as `undefined` doesn't have the `toUpperCase()` method, we'll get an error.

-There are two variants here:

-1. Use `str.charAt(0)`, as it always returns a string (maybe empty).
-2. Add a test for an empty string.

-Here's the 2nd variant:

```js run demo
function ucFirst(str) {

diff --git a/1-js/05-data-types/03-string/1-ucfirst/task.md b/1-js/05-data-types/03-string/1-ucfirst/task.md
@@ -2,9 +2,9 @@ importance: 5

---

-# Uppercase the first character

-Write a function `ucFirst(str)` that returns the string `str` with the uppercased first character, for instance:

```js
ucFirst("john") == "John";

diff --git a/1-js/05-data-types/03-string/2-check-spam/solution.md b/1-js/05-data-types/03-string/2-check-spam/solution.md
@@ -1,4 +1,4 @@
-To make the search case-insensitive, let's bring the string to lower case and then search:

```js run demo
function checkSpam(str) {

diff --git a/1-js/05-data-types/03-string/3-truncate/solution.md b/1-js/05-data-types/03-string/3-truncate/solution.md
@@ -1,6 +1,6 @@
-The maximal length must be `maxlength`, so we need to cut it a little shorter, to give space for the ellipsis.

-Note that there is actually a single Unicode character for an ellipsis. That's not three dots.

```js run
function truncate(str, maxlength) {

diff --git a/1-js/05-data-types/03-string/3-truncate/task.md b/1-js/05-data-types/03-string/3-truncate/task.md
@@ -2,13 +2,13 @@ importance: 5

---

-# Truncate the text

-Create a function `truncate(str, maxlength)` that checks the length of the `str` and, if it exceeds `maxlength` -- replaces the end of `str` with the ellipsis character `"…"`, to make its length equal to `maxlength`.

-The result of the function should be the truncated (if needed) string.

-For instance:

```js
truncate("What I'd like to tell on this topic is:", 20) = "What I'd like to te…"

diff --git a/1-js/05-data-types/03-string/4-extract-currency/task.md b/1-js/05-data-types/03-string/4-extract-currency/task.md
@@ -2,15 +2,14 @@ importance: 4

---

-# Extract the money

-We have a cost in the form `"$120"`. That is: the dollar sign goes first, and then the number.

-Create a function `extractCurrencyValue(str)` that would extract the numeric value from such string and return it. 

-The example:

```js
alert( extractCurrencyValue('$120') === 120 ); // true
```
-
-Original file line number
+Diff line change
@@ Expand Up / @@ -2,9 +2,9 @@ importance: 5 @@
     ---
-    # Uppercase the first character
-    Write a function `ucFirst(str)` that returns the string `str` with the uppercased first character, for instance:
     ```js
     ucFirst("john") == "John";
@@ Expand Down @@