[typescript/en] Add doc for for-of and for-in loops in Typescri… (#3548)

[typescript/en] Add doc for for-of and for-in loops in Typescript

typescript.html.markdown

@@ -223,6 +223,30 @@ moreNumbers[5] = 5; // Error, elements are read-only
 moreNumbers.push(5); // Error, no push method (because it mutates array)
 moreNumbers.length = 3; // Error, length is read-only
 numbers = moreNumbers; // Error, mutating methods are missing
+
+// Iterators and Generators
+
+// for..of statement
+// iterate over the list of values on the object being iterated
+let arrayOfAnyType = [1, "string", false];
+for (const val of arrayOfAnyType) {
+    console.log(val); // 1, "string", false
+}
+
+let list = [4, 5, 6];
+for (const i of list) {
+   console.log(i); // "4", "5", "6"
+}
+
+// for..in statement
+// iterate over the list of keys on the object being iterated
+for (const i in list) {
+   console.log(i); // "0", "1", "2",
+}
+
+
+
+
 ```
 
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