feat: add typescript solution to lc problem: No.2278

No.2278.Percentage of Letter in String

Author: zhaocchen

solution/2200-2299/2278.Percentage of Letter in String/README.md

@@ -102,7 +102,14 @@ func percentageLetter(s string, letter byte) int {
 ### **TypeScript**
 
 ```ts
-
+function percentageLetter(s: string, letter: string): number {
+    let count = 0;
+    let total = s.length;
+    for (let i of s) {
+        if (i === letter) count++;
+    }
+    return Math.floor(count / total * 100);
+};
 ```
 
 ### **...**

solution/2200-2299/2278.Percentage of Letter in String/README_EN.md

@@ -92,7 +92,14 @@ func percentageLetter(s string, letter byte) int {
 ### **TypeScript**
 
 ```ts
-
+function percentageLetter(s: string, letter: string): number {
+    let count = 0;
+    let total = s.length;
+    for (let i of s) {
+        if (i === letter) count++;
+    }
+    return Math.floor(count / total * 100);
+};
 ```
 
 ### **...**

solution/2200-2299/2278.Percentage of Letter in String/Solution.ts

@@ -0,0 +1,8 @@
+function percentageLetter(s: string, letter: string): number {
+    let count = 0;
+    let total = s.length;
+    for (let i of s) {
+        if (i === letter) count++;
+    }
+    return Math.floor(count / total * 100);
+};