Completed week-2 assignments in 01-async-js folder

week-2/01-async-js/easy/counter.js

@@ -0,0 +1,22 @@
+// ## Create a counter in JavaScript
+
+// We have already covered this in the second lesson, but as an easy recap try to code a counter in Javascript
+// It should go up as time goes by in intervals of 1 second
+
+let count = 0;
+
+function counter(){
+    setInterval(() =>{
+        count++;
+        console.log(count);
+    }, 1000);
+}
+
+function counter(){
+    count++;
+    console.log(count);
+
+    setTimeout(counter, 1000);
+}
+counter();
+

week-2/01-async-js/easy/output.txt

@@ -0,0 +1 @@
+wfwvvscsadwqfdqfd

week-2/01-async-js/easy/read-file-content.js

@@ -0,0 +1,41 @@
+const fs = require ('fs').promises;
+const prompt = require('prompt-sync')();
+
+async function expensiveOperation(n){
+    let res = 0;
+    for(let i = 0; i< n; i++){
+
+        res += Math.sqrt(i) * Math.random();
+    }
+
+    console.log(`Expensive computation result: ${res}`);
+}
+async function readFileContent(){
+
+    const FILE_PATH = "3-read-from-file.md";
+
+    try{
+        const data = await fs.readFile(FILE_PATH, "utf-8");
+        console.log("File Content: ");
+        console.log(data);
+    }
+    catch(err){
+        console.error("Error Reading the file content: ", err.message);
+    }
+
+}
+
+async function main(){
+
+    const iterations = prompt('How Many Iterations? ');
+    console.log(`No of Iterations are , ${iterations}!`);
+    try{
+        await Promise.all([readFileContent(), expensiveOperation(iterations)]);
+    }
+    catch(err){
+        console.error('Program error:', error.message);
+    }
+
+}
+
+main();

week-2/01-async-js/easy/write-file-content.js

@@ -0,0 +1,48 @@
+const fs = require ('fs').promises;
+const prompt = require('prompt-sync')();
+
+async function expensiveOperation(n){
+    let res = 0;
+    for(let i = 0; i< n; i++){
+
+        res += Math.sqrt(i) * Math.random();
+    }
+
+    console.log(`Expensive computation result: ${res}`);
+}
+async function writeFileContent(content){
+
+    const FILE_PATH = "output.txt";
+
+    try{
+        await fs.writeFile(FILE_PATH, content,  "utf-8");
+
+        console.log("Succesfully wrote to the file");
+
+        const data = await fs.readFile(FILE_PATH, "utf-8");
+        console.log('File Content: ');
+        console.log(data);
+    }
+    catch(err){
+        console.error("Error Writing to the file: ", err.message);
+    }
+
+}
+
+async function main() {
+    const content = prompt('Enter File Content to write to the file: ');
+    const iterations = parseInt(prompt('How Many Iterations? '));
+
+    try {
+      await Promise.all([
+        writeFileContent(content),
+        expensiveOperation(iterations)
+      ]);
+      console.log('All operations completed successfully.');
+    } catch (err) {
+      console.error('Program error:', err.message);
+    }
+  }
+
+
+main();

week-2/01-async-js/hard (promises)/1-promisify-setTimeout.js

@@ -3,6 +3,21 @@
 */
 
 function wait(n) {
+
+    return new Promise((resolve) =>{
+        setTimeout(resolve, n * 1000);
+    });
 }
 
-module.exports = wait;
+
+async function main(){
+    console.log('Start');
+
+    await wait(5);
+
+    console.log('After 5 seconds');
+}
+
+main();
+
+module.exports = wait;

week-2/01-async-js/hard (promises)/2-sleep-completely.js

@@ -5,6 +5,25 @@
  */
 
 function sleep(milliseconds) {
+
+    return new Promise((resolve) =>{
+        // setTimeout(resolve, milliseconds);
+        // console.log('After resolve');
+
+        const start = Date.now();
+        while(Date.now() - start < milliseconds){
+            continue;
+        }
+        resolve();
+    })
+} 
+
+async function main(n){
+    console.log('Before Sleep');
+    await sleep(n);
+    console.log(`After Sleep for ${n} milliseconds`);
+
 }
 
+main(2000);
 module.exports = sleep;

week-2/01-async-js/hard (promises)/3-promise-all.js

@@ -5,19 +5,36 @@
  */
 
 function wait1(t) {
-
+    return new Promise((resolve) =>{
+        setTimeout(resolve, t*1000);
+    })
 }
 
 function wait2(t) {
-
+    return new Promise((resolve) =>{
+        setTimeout(resolve, t*1000);
+    })
 }
 
 function wait3(t) {
-
+    return new Promise((resolve) =>{
+        setTimeout(resolve, t*1000);
+    })
 }
 
-function calculateTime(t1, t2, t3) {
-
+async function calculateTime(t1, t2, t3) {
+    const start = Date.now();
+    return Promise.all([
+        wait1(t1),
+        wait2(t2),
+        wait3(t3)
+    ]).then(() =>{
+        const end = Date.now();
+        return end - start;
+    });
 }
 
+calculateTime(1,2,3).then((time)=>{
+    console.log(`Time Take: ${time} ms`);
+});
 module.exports = calculateTime;

week-2/01-async-js/hard (promises)/4-promise-chain.js

@@ -5,20 +5,38 @@
  * Compare it with the results from 3-promise-all.js
  */
 
-function wait1(t) {
 
+function wait1(t) {
+    return new Promise((resolve) =>{
+        setTimeout(resolve, t*1000);
+    })
 }
 
 function wait2(t) {
-
+    return new Promise((resolve) =>{
+        setTimeout(resolve, t*1000);
+    })
 }
 
 function wait3(t) {
-
+    return new Promise((resolve) =>{
+        setTimeout(resolve, t*1000);
+    })
 }
 
 function calculateTime(t1, t2, t3) {
 
+    const start = Date.now();
+    return wait1(t1)
+    .then(() => wait2(t2)
+    .then(() =>wait3(t3)
+    .then(() =>{
+        const end = Date.now(); 
+        return end - start;
+    })));
 }
-
+calculateTime(1,2,3)
+.then((time)=>{
+    console.log(`Time taken: ${time}`);
+});
 module.exports = calculateTime;

week-2/01-async-js/medium/clock.js

@@ -0,0 +1,18 @@
+function updateClock() {
+    const now = new Date();
+
+    // Format for 24-hour time (HH:MM:SS)
+    const time24 = now.toTimeString().split(' ')[0];
+
+    // Format for 12-hour time (HH:MM:SS AM/PM)
+    const time12 = now.toLocaleTimeString('en-US', {
+        hour12: true,
+        hour: '2-digit',
+        minute: '2-digit',
+        second: '2-digit'
+    });
+
+    setTimeout(updateClock, 1000);
+}
+
+updateClock();

week-2/01-async-js/medium/file-cleaner.js

@@ -0,0 +1,37 @@
+// ## File cleaner
+// Read a file, remove all the extra spaces and write it back to the same file.
+
+// For example, if the file input was
+// ```
+// hello     world    my    name   is       raman
+// ```
+
+// After the program runs, the output should be
+
+// ```
+// hello world my name is raman
+// ```
+
+
+const fs = require('fs').promises;
+
+const FILE_PATH = 'file-cleaner.txt';
+
+async function cleanContent(filepath){
+    try{
+        const data = await fs.readFile(filepath, 'utf-8');
+        const replacedContent = data.replace(/\s+/g, ' ').trim();
+        await fs.writeFile(filepath, replacedContent);
+
+        console.log('File Content Has Been Cleaned !!');
+
+        const newData = await fs.readFile(filepath, 'utf-8');
+        console.log('New Content of the File: ');
+        console.log(newData);
+    }
+    catch(err){
+        console.error('Error Processing the file: ', err.message);
+    }
+}
+
+cleanContent(FILE_PATH);

week-2/01-async-js/medium/file-cleaner.txt

@@ -0,0 +1 @@
+hello this is a sample text that needs to be cleaned