Challenge 25 & 26 Added

Author: sahilatahar

README.md

@@ -218,6 +218,22 @@ Write a function called `findLongestWord` that takes string as argument `sentenc
 
 [Solution Explanation](./solutions/ch_24_Find_Longest_Word_In_Sentence/readme.md)
 
+## Challenge 25: Check Empty Object
+
+Write a function to check if an object is empty or not.
+
+Write a function called `isObjEmpty` that takes an object `obj` as arguments will return true if it is empty otherwise false.
+
+[Solution Explanation](./solutions/ch_25_Check_Empty_Object/readme.md)
+
+## Challenge 26: Convert Time from 12Hrs to 24Hrs Format
+
+Write a function which can convert time from 12 hours format to 24 hours format.
+
+Write a function called `convertTo24HrsFormat` which take `time` as parameter in `HH:MMAM` format. for example, `12:10AM`.
+
+[Solution Explanation](./solutions/ch_26_Convert_Time_To_24_Format/readme.md)
+
 <!-- Add new challenges before this comment -->
 
 ## Contributors

solutions/ch_25_Check_Empty_Object/answer.js

@@ -0,0 +1,4 @@
+// Function to check whether an object is empty or not
+function isObjEmpty(obj) {
+    return Object.keys(obj).length === 0;
+}

solutions/ch_25_Check_Empty_Object/readme.md

@@ -0,0 +1,19 @@
+# Challenge 25: Check Empty Object
+
+Write a function to check if an object is empty or not.
+
+Write a function called `isObjEmpty` that takes an object `obj` as arguments will return true if it is empty otherwise false.
+
+## Answer
+
+```javascript
+// Function to check whether an object is empty or not
+function isObjEmpty(obj) {
+  return Object.keys(obj).length === 0;
+}
+```
+
+## Answer Explanation
+
+Here is a function called `isObjEmpty` that takes an object as arguments and checking the length of `obj` keys using object `keys()` method and it will return true if length is zero otherwise false.
+

solutions/ch_26_Convert_Time_To_24_Format/answer.js

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+// Function to convert 12Hrs time to 24Hrs time.
+function convertTo24HrsFormat(time) {
+
+    let timeArray = time.split(':');
+    let hour = Number(timeArray[0]); // Convert hour into number from string
+
+    if (time.endsWith('PM')) {
+        // if hour is not 12 then add 12 hour.
+        hour = hour !== 12 ? hour + 12 : hour;
+    } else {
+        // if time is AM and if hour is 12 then subtract 12 hour.
+        hour = hour === 12 ? hour - 12 : hour;
+    }
+    time = `${hour.toString().padStart(2, 0)}:${timeArray[1].slice(0, -2)}`;
+
+    return time;
+}

solutions/ch_26_Convert_Time_To_24_Format/readme.md

@@ -0,0 +1,31 @@
+# Challenge 26: Convert Time from 12Hrs to 24Hrs Format
+
+Write a function which can convert time from 12 hours format to 24 hours format.
+
+Write a function called `convertTo24HrsFormat` which take `time` as parameter in `HH:MMAM` format. for example, `12:10AM`.
+
+## Answer
+
+```javascript
+// Function to convert 12Hrs time to 24Hrs time.
+function convertTo24HrsFormat(time) {
+
+    let timeArray = time.split(':');
+    let hour = Number(timeArray[0]); // Convert hour into number from string
+
+    if (time.endsWith('PM')) {
+        // if hour is not 12 then add 12 hour.
+        hour = hour !== 12 ? hour + 12 : hour;
+    } else {
+        // if time is AM and if hour is 12 then subtract 12 hour.
+        hour = hour === 12 ? hour - 12 : hour;
+    }
+    time = `${hour.toString().padStart(2, 0)}:${timeArray[1].slice(0, -2)}`;
+
+    return time;
+}
+```
+
+## Answer Explanation
+
+Function `convertTo24HrsFormat` takes `time` as parameter and split it into two parts where first part will be `HH` and second part will be `MMAM` or `MMPM`. After that convert hours into Number data type and check condition using string `endsWith()` method. if condition and manipulate time hours and after that remove AM or PM and return time in 24Hrs format.