week-2 assignments completed

01-js/easy/anagram.js

@@ -5,7 +5,24 @@
 */
 
 function isAnagram(str1, str2) {
-
+  return sort_str(str1)===sort_str(str2)
+}
+function sort_str(str){
+  str = str.toLowerCase()
+  let sorted_str = "0"
+  for(let i=0;i<str.length;i++){
+      for(let j=0;j<sorted_str.length;j++){
+          if(sorted_str[j]>str[i]){
+              sorted_str = sorted_str.substring(0,j)+str[i]+sorted_str.substring(j)
+              break
+          }
+          if(j==sorted_str.length-1) {
+              sorted_str+= str[i]
+              break
+          }
+      }
+  }
+  return sorted_str
 }
 
 module.exports = isAnagram;

01-js/easy/expenditure-analysis.js

@@ -14,7 +14,27 @@
 */
 
 function calculateTotalSpentByCategory(transactions) {
-  return [];
+  let ans=[];
+  for(let i=0;i<transactions.length;i++){
+    let obj1 = transactions[i]
+    let b= false 
+    let index=-1;
+    for(let j=0;j<ans.length;j++){
+      if(ans[j].category==obj1.category){
+        b= true;
+        index = j;
+        break;
+      }
+    }
+    if(!b){
+      let obj2 = { "category" : obj1.category, "totalSpent" : obj1.price}
+      ans.push(obj2);
+    } 
+    else{
+      ans[index].totalSpent += obj1.price;
+    }
+  }
+  return ans;
 }
 
 module.exports = calculateTotalSpentByCategory;

01-js/easy/findLargestElement.js

@@ -6,7 +6,11 @@
 */
 
 function findLargestElement(numbers) {
-
+    largestELement = numbers[0]
+    for(let i=0;i<numbers.length;i++){
+        if(numbers[i]>largestELement) largestELement=numbers[i]
+    }
+    return largestELement    
 }
 
 module.exports = findLargestElement;

01-js/hard/calculator.js

@@ -16,6 +16,33 @@
   Once you've implemented the logic, test your code by running
 */
 
-class Calculator {}
+class Calculator {
+  constructor(){
+    this.result=0;
+  }
+  add(num){
+    this.result += num;
+  }
+  subtract(num){
+    this.result -= num;
+  }
+  multiply(num){
+    this.result *= num;
+  }
+  divide(num){
+    if(num!=0) this.result /= num;
+    else throw ErrorEvent;
+  }
+  clear(){
+    this.result =0;
+  }
+  getResult(){
+    return this.result ; 
+  }
+  calculate(expression){
+    this.result = (eval(expression))  
+    if (this.result==Infinity) throw ErrorEvent;
+  }
+}
 
 module.exports = Calculator;

01-js/hard/todo-list.js

@@ -11,7 +11,30 @@
 */
 
 class Todo {
-
+  constructor(){
+    this.todos =[] ;
+  }
+
+  add(todo){
+    this.todos.push(todo);
+  }
+  remove(index){
+    if(index<this.todos.length && index>=0) this.todos.splice(index,1);
+  }
+  update(index ,updatedTodo){
+    if(index<this.todos.length && index>=0) this.todos[index] = updatedTodo;
+  }
+  get(index){
+    let r= this.todos[index];
+    if(r) return r;
+    else  return null;
+  }
+  getAll(){
+    return this.todos;
+  }
+  clear(){
+    this.todos = [];
+  }
 }
 
 module.exports = Todo;

01-js/medium/countVowels.js

@@ -6,7 +6,11 @@
 */
 
 function countVowels(str) {
-    // Your code here
+  str= str.toLowerCase();
+  let vowels = "aeiou";
+  let count=0;
+  for(let i=0;i<str.length;i++) if(vowels.indexOf(str.charAt(i))>=0) count++;
+  return count;
 }
 
 module.exports = countVowels;

01-js/medium/palindrome.js

@@ -4,6 +4,11 @@
 */
 
 function isPalindrome(str) {
+  let str2= str.toLowerCase();
+  str=""
+  for(let i=0;i<str2.length;i++) if(str2[i]>='a'&& str2[i]<='z') str+=str2[i];
+  let n= str.length -1;
+  for(let i=0;i<n/2;i++) if(!(str[i]==str[n-i])) return false;
   return true;
 }
 

01-js/medium/times.js

@@ -9,5 +9,11 @@ There is no automated test for this one, this is more for you to understand time
 */
 
 function calculateTime(n) {
-    return 0.01;
+    let num=0;
+    let date = new Date();
+    console.log(date.getTime())
+    for(let i=0;i<n;i++) num+= i;
+    let date2 = new Date();
+    console.log((date2.getTime()-date.getTime())/1000);
+    return num;
 }

week-2/01-async-js/easy/1-counter.js

@@ -0,0 +1,13 @@
+// ## 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 num=0;
+
+function r(){
+    num+=1
+    console.log(num);
+}
+
+setInterval(r,1000)

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

@@ -0,0 +1,13 @@
+// ## Counter without setInterval
+// Without using setInterval, try to code a counter in Javascript. There is a hint at the bottom of the file if you get stuck.
+// (Hint: setTimeout)
+
+let num =0;
+
+function counter(){
+    num+=1;
+    console.log(num);
+    setTimeout(counter,1000);
+}
+
+counter()

week-2/01-async-js/easy/3-read-from-file.js

@@ -0,0 +1,13 @@
+// ## Reading the contents of a file
+
+// Write code to read contents of a file and print it to the console. 
+// You can use the fs library to as a black box, the goal is to understand async tasks. 
+// Try to do an expensive operation below the file read and see how it affects the output. 
+// Make the expensive operation more and more expensive and see how it affects the output. 
+
+const fs = require('fs');
+
+fs.readFile('./week-2/01-async-js/easy/a.txt',(err,data)=>{
+    for(let i=0;i<10000000000;i++){};
+    console.log(data.toString());
+})

week-2/01-async-js/easy/4-write-to-file.js

@@ -0,0 +1,18 @@
+// ## Write to a file
+// Using the fs library again, try to write to the contents of a file.
+// You can use the fs library to as a black box, the goal is to understand async tasks.
+
+const fs = require('fs');
+
+async function k(){
+    fs.readFile("./week-2/01-async-js/easy/a.txt",(err,data)=>{
+        console.log(data.toString());
+        fs.writeFile("./week-2/01-async-js/easy/a.txt","this file is written by write-to-file.js file",()=>{
+            fs.readFile("./week-2/01-async-js/easy/a.txt",(err,data)=>{
+                console.log(data.toString());
+            })
+        })
+    })   
+}
+
+k()

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

@@ -0,0 +1 @@
+most beautiful file

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

@@ -3,6 +3,9 @@
 */
 
 function wait(n) {
+    let p = new Promise((resolve)=>{
+        setTimeout(resolve,n*1000)
+    })
+    return p;
 }
-
 module.exports = wait;

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

@@ -4,7 +4,13 @@
  * the function should return a promise just like before
  */
 
-function sleep(milliseconds) {
+async function sleep(milliseconds) {
+    let p = await new Promise( (reslove)=>{
+            setTimeout(reslove,milliseconds);
+        }  
+    )
+    return p;
+
 }
 
 module.exports = sleep;