diff --git a/.vscode/launch.json b/.vscode/launch.json
new file mode 100644
index 0000000..eab977d
--- /dev/null
+++ b/.vscode/launch.json
@@ -0,0 +1,17 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "pwa-node",
+            "request": "launch",
+            "name": "Launch Program",
+            "skipFiles": [
+                "<node_internals>/**"
+            ],
+            "program": "${file}"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/AngkaPalindrom.js b/AngkaPalindrom.js
new file mode 100644
index 0000000..85b0add
--- /dev/null
+++ b/AngkaPalindrom.js
@@ -0,0 +1,23 @@
+/** input 4 digit, cek apakah angka palindrome */
+
+function isPalindrome(angka){
+    if(isNaN(angka)){
+        return angka+" is not an number"
+    }
+
+    else{
+        if(String(angka) == String(angka).split('').reverse().join('')){
+            return angka+" is palindrome";
+        }
+        else{
+            return angka+" is not palindrome";
+        }
+    }
+}
+
+
+console.log(isPalindrome("abcd"));//abcd is not an number
+console.log(isPalindrome("123a"));//123a is not an number
+console.log(isPalindrome("1234"));//1234 is not palindrome
+console.log(isPalindrome(1221));//1221 is palindrome
+console.log(isPalindrome("8888"));//8888 is palindrome
\ No newline at end of file
diff --git a/AreaCircle.js b/AreaCircle.js
new file mode 100644
index 0000000..6460f31
--- /dev/null
+++ b/AreaCircle.js
@@ -0,0 +1,25 @@
+/** 
+  Diketahui rumus area = pi * radius * radius dimana pi = 3.14159, r = radius buat function dengan nama getAreaCircle(r)
+  Output Contraint : 
+  getAreaCircle('-1'); //return radius -1 <= 0, try higher
+  getAreaCircle('a');  //return Inputan harus dalam angka
+  getAreaCircle(5);    //retun 78.53975
+ */
+
+function getAreaCircle(r) {
+    if(r<=0){
+        return "radius -1 <= 0, try higher"
+    }
+
+    else if(isNaN(r)){
+        return "Inputan harus dalam angka"
+    }
+    else{
+        return Math.PI.toFixed(5)*Math.pow(r,2);
+    }
+}
+
+
+console.log(getAreaCircle('-1')); //return radius -1 <= 0, try higher
+console.log(getAreaCircle('a'));  //return Inputan harus dalam angka
+console.log(getAreaCircle(5).toFixed(5));    //retun 78.53975
\ No newline at end of file
diff --git a/Bill.js b/Bill.js
new file mode 100644
index 0000000..554b3fe
--- /dev/null
+++ b/Bill.js
@@ -0,0 +1,28 @@
+/** hitung total gaji karyawan */
+
+function totalGaji(gaji1, gaji2, gaji3) {
+   let bayar1=gaji1+(taxGaji(gaji1)*gaji1);
+   let bayar2=gaji2+(taxGaji(gaji2)*gaji2);
+   let bayar3=gaji3+(taxGaji(gaji3)*gaji3);
+   let total=bayar1+bayar2+bayar3;
+   return "Total gaji yang harus dibayar :\nEmp1 : Rp."+gaji1+" + Pajak("+taxGaji(gaji1)*100+"%)=Rp."+bayar1+"\nEmp2 : Rp."+gaji2+" + Pajak("+taxGaji(gaji2)*100+"%)=Rp."+bayar2+"\nEmp3 : Rp."+gaji3+" + Pajak("+taxGaji(gaji3)*100+"%)=Rp."+bayar3+"\nTotal : Rp."+total;
+}
+
+function taxGaji(gaji) {
+    if (gaji >= 10000) {
+        return (10 / 100).toFixed(2)
+    } else if (gaji >= 1000 && gaji < 10000) {
+        return (5 / 100).toFixed(2)
+    } else if (gaji >= 100 && gaji < 1000) {
+        return (2 / 100).toFixed(2)
+    }
+}
+
+console.log(totalGaji(500, 2000, 12000));
+/**
+    Total gaji yang harus dibayar :  
+    Emp1 : Rp.500 + Pajak(2%)=Rp.510
+    Emp1 : Rp.2000 + Pajak(5%)=Rp.2100
+    Emp1 : Rp.12000 + Pajak(10%)=Rp.13200
+    Total : Rp.15810
+ */
\ No newline at end of file
diff --git a/ConvertRupiah.js b/ConvertRupiah.js
new file mode 100644
index 0000000..51a05b8
--- /dev/null
+++ b/ConvertRupiah.js
@@ -0,0 +1,26 @@
+/**
+ * Convert rupiah to other currency
+ */
+
+function convertToRupiah(money,type){
+    if(type=="yen"){
+        let result=money*130.12;
+        return Intl.NumberFormat('ID',{style:'currency',currency:'IDR',maximumFractionDigits: 0, minimumFractionDigits: 0}).format(result)
+    }
+    else if(type=="usd"){
+        let result=money*14382.5;
+        return Intl.NumberFormat('ID',{style:'currency',currency:'IDR',maximumFractionDigits: 0, minimumFractionDigits: 0}).format(result)
+    }
+    else if(type=="euro"){
+        let result=money*16000;
+        return Intl.NumberFormat('ID',{style:'currency',currency:'IDR',maximumFractionDigits: 0, minimumFractionDigits: 0}).format(result)
+    }
+    else{
+        return "no match type currency"
+    }
+}
+
+console.log(convertToRupiah(1000,'yen'));//1000 yen  = Rp.130.120
+console.log(convertToRupiah(100,'usd'));//100 dollar  = Rp.1.438.250
+console.log(convertToRupiah(100,'euro'));//100 dollar  = Rp.1.600.000
+console.log(convertToRupiah(100,''));//no match type currency
\ No newline at end of file
diff --git a/ConvertSuhu.js b/ConvertSuhu.js
new file mode 100644
index 0000000..1cadefc
--- /dev/null
+++ b/ConvertSuhu.js
@@ -0,0 +1,18 @@
+/**
+ * konversi fareinheit to kelvin
+ * rumus Kelvin = (Fareinheit + 459.67)/1.8
+ * 
+ */
+
+ function fareinheitToKelvin(fareinheit){
+    if(isNaN(fareinheit)){
+        return "Fareinheit must an number"
+    }
+    else{
+        return "Convert Fareinheit ("+fareinheit+") to Kelvin = "+ ((fareinheit + 459.67)/1.8).toFixed();
+    }
+}
+
+console.log(fareinheitToKelvin(45)); //Convert Fareinheit (45) to Kelvin = 280
+console.log(fareinheitToKelvin("1")); //Convert Fareinheit (1) to Kelvin = 811
+console.log(fareinheitToKelvin("F")); //Fareinheit must an number
\ No newline at end of file
diff --git a/DistanceTravel.js b/DistanceTravel.js
new file mode 100644
index 0000000..f5ae8ed
--- /dev/null
+++ b/DistanceTravel.js
@@ -0,0 +1,23 @@
+/** hitung jarak antar kota
+ *  dimana rumus jarak S = 1/2*a*t^2
+ *  function calculateDistance(a,t), 
+ *  where a = accelaration in number
+ *  t : time
+ */
+
+ function calculateDistance(a, t){
+    if(a<=0 || t<=0){
+        return "Accelaration or time must be >= 0"
+    }
+
+    else if(isNaN(a) || isNaN(t)){
+        return "input must an number"
+    }
+    else{
+        return "Jarak yang ditempuh adalah "+0.5*a*Math.pow(t,2)+" meter/s";
+    }
+}
+
+console.log(calculateDistance("a","t"));//input must an number
+console.log(calculateDistance(-1,9)); //Accelaration or time must be >= 0
+console.log(calculateDistance(50,60)); //Jarak yang ditempuh adalah 90000 meter/s
\ No newline at end of file
diff --git a/ElapsedTimes.js b/ElapsedTimes.js
new file mode 100644
index 0000000..2f9db7e
--- /dev/null
+++ b/ElapsedTimes.js
@@ -0,0 +1,31 @@
+/**
+ * hitung detik ke dalam day, hour, minute and seconds
+ */
+
+
+function getPeriodTimes(seconds) {
+    if(isNaN(seconds)){
+        return seconds+" is not number"
+    }
+    else{
+        const secondsInAMinute = 60;
+        const secondsInAnHour  = 60 * secondsInAMinute;
+        const secondsInADay    = 24 * secondsInAnHour;
+        
+        const days = Math.floor(seconds / secondsInADay);
+
+        const hourSeconds = seconds % secondsInADay;
+        const hours = Math.floor(hourSeconds / secondsInAnHour);
+
+        const minuteSeconds = hourSeconds % secondsInAnHour;
+        const minutes = Math.floor(minuteSeconds / secondsInAMinute);
+
+        const remainingSeconds = minuteSeconds % secondsInAMinute;
+        const second = Math.ceil(remainingSeconds);
+
+        return days+" hari "+hours+" jam "+minutes+" menit "+second+" detik";
+    }    
+}
+
+console.log(getPeriodTimes("700005A"));//700005A is not number
+console.log(getPeriodTimes("700005"));//8 hari 2 jam 26 menit 45 detik
\ No newline at end of file
diff --git a/GetDays.js b/GetDays.js
new file mode 100644
index 0000000..2776ca1
--- /dev/null
+++ b/GetDays.js
@@ -0,0 +1,28 @@
+/** Display year is kabisat and display month */
+
+function getDays(month,year){
+    if(isNaN(month) && !isNaN(year)){
+        return "inputan bulan harus dalam integer"
+    }
+    else if(!isNaN(month) && isNaN(year)){
+        return "inputan tahun harus dalam integer"
+    }
+    else if(isNaN(month) && isNaN(year)){
+        return "inputan bulan & tahun harus dalam integer"
+    }
+    else{
+        if(year%4==0){
+            return "This month has "+new Date(year, month, 0).getDate()+" days, "+year+" adalah tahun kabisat";
+        }
+        else if(year%4!=0){
+            return "This month has "+new Date(year, month, 0).getDate()+" days";
+        }
+        
+    }
+}
+
+console.log(getDays("a",2021)); //inputan bulan harus dalam integer
+console.log(getDays("2","year")); //inputan tahun harus dalam integer
+console.log(getDays("m","year"));//inputan bulan & tahun harus dalam integer
+console.log(getDays(2,2000)); //This month has 29 days, 2000 adalah tahun kabisat
+console.log(getDays(8,2021)); //This month has 31 hari
\ No newline at end of file
diff --git a/HeaviestPerson.js b/HeaviestPerson.js
new file mode 100644
index 0000000..371204e
--- /dev/null
+++ b/HeaviestPerson.js
@@ -0,0 +1,9 @@
+/**
+ * hitung orang yg memiliki berat badan paling tinggi
+ */
+
+function getHeavier(w1,wg2,wg3){
+    return Math.max(w1,wg2,wg3);    
+}
+
+console.log(getHeavier(12,45,70));//70
\ No newline at end of file
diff --git a/JarakKordinat.js b/JarakKordinat.js
new file mode 100644
index 0000000..03d1ce0
--- /dev/null
+++ b/JarakKordinat.js
@@ -0,0 +1,18 @@
+/**
+ * Menghitung jarak kordinat
+ * 𝑑 = √(𝑥1 − 𝑥2)^2 + (𝑦1 −𝑦2)^2
+ */
+
+function getCordinat(x1,y1,x2,y2) {
+    if(isNaN(x1) || isNaN(y1) || isNaN(x2) || isNaN(y2)){
+        return "input kordinat dalam angka";
+    }
+    else{
+        return Math.sqrt(Math.pow(x1-x2,2)+Math.pow(y1-y2,2));
+    }
+}
+
+console.log(getCordinat(3,4,-4,-5)); //9
+console.log(getCordinat("1","2","-1","-2")); //1
+console.log(getCordinat("x","2","-y","-2")); //input kordinat dalam angka
+console.log(getCordinat(3.2,4.5,-4.4,-5)); //13.695801445917125
\ No newline at end of file
diff --git a/Prosentase.js b/Prosentase.js
new file mode 100644
index 0000000..7bd413c
--- /dev/null
+++ b/Prosentase.js
@@ -0,0 +1,22 @@
+/** Buat program untuk menampilkan prosentasi dari income*/
+
+function getProsentase(start,end){
+    if(isNaN(start) || isNaN(end)){
+        return start+" or "+end+" harus dalam angka"
+    }
+    else{
+        let increase=((end-start)/start)*100;
+        if(increase<0){
+            return "Total penurunan income "+Math.floor(increase)+"%";
+        }
+        else{
+            return "Total kenaikan income "+Math.ceil(increase)+"%";
+        }
+        
+    }
+}
+
+console.log(getProsentase("abc","bca"));//abc or bca harus dalam angka
+console.log(getProsentase(600000.00,750000.00));//Total kenaikan income 25%
+console.log(getProsentase(750000.00,650000.00));//Total penurunan income -14%
+
diff --git a/SalesTax.js b/SalesTax.js
new file mode 100644
index 0000000..ddb82d5
--- /dev/null
+++ b/SalesTax.js
@@ -0,0 +1,31 @@
+/**
+ * Hitung pajak dari total penjualan
+ * function getSalesTax(price, tax)
+ */
+
+ function getSalesTax(price, tax) {
+    if(isNaN(price) && !isNaN(tax)){
+        return "Price harus dalam angka"
+    }
+    else if(!isNaN(price) && isNaN(tax)){
+        return "Pajak harus dalam angka"
+    }
+    else if(isNaN(price) && isNaN(tax)){
+        return "Price & Pajak harus dalam angka"
+    }
+    else{
+        let sum=price+tax;
+        return "Total Sales : Rp."+price+"\nPajak : "+tax+"\nTotalHarga+Pajak : Rp."+sum;
+    }
+}
+
+console.log(getSalesTax("a", 1));//Price harus dalam angka
+console.log(getSalesTax(500, "pajak"));//Price & Pajak harus dalam angka
+console.log(getSalesTax("harga", "pajak"));//Pajak harus dalam angka
+console.log(getSalesTax(4500, 5));
+/**
+ Total Sales : Rp.4500
+ Pajak : 0.5
+ TotalHarga+Pajak : Rp.4505
+ 
+*/
\ No newline at end of file
diff --git a/SalesTaxRateDiscount.js b/SalesTaxRateDiscount.js
new file mode 100644
index 0000000..858175f
--- /dev/null
+++ b/SalesTaxRateDiscount.js
@@ -0,0 +1,35 @@
+ /**
+  * hitung sales discount plus tax rate
+  * function getSalesDiscount
+  */
+
+function getSalesDiscount(price,tax,discount){
+    if(isNaN(price) && !isNaN(tax) && !isNaN(discount)){
+        return "Price harus dalam angka"
+    }
+    else if(!isNaN(price) && isNaN(tax) && !isNaN(discount)){
+        return "Pajak harus dalam angka"
+    }
+    else if(isNaN(price) && isNaN(tax) && isNaN(discount)){
+        return "Price,Pajak & Discount harus dalam angka"
+    }
+    else{
+        let dis=price-(discount/100)*price;
+        let afterTax=dis/10;
+        let total=dis+afterTax;
+        return "Total Sales : Rp."+price+"\nDiscount ("+discount+"%) : Rp."+(discount/100)*price+"\nPriceAfterDiscount : Rp."+dis+"\nPajak ("+tax+"%) : Rp."+afterTax+"\n----------------------------------\nTotalPayment : Rp."+total;
+    }
+}
+
+console.log(getSalesDiscount("a", 1,5));//Price harus dalam angka
+console.log(getSalesDiscount(500, "pajak",5));//Pajak harus dalam angka
+console.log(getSalesDiscount("harga", "pajak","discount"));//Price, Tax & Discount harus dalam angka
+console.log(getSalesDiscount(4500, 10,5));
+/**
+   Total Sales 	: Rp.4500 
+   Discount (5%) 	: Rp.225
+   PriceAfterDiscount 	: Rp.4275
+   Pajak (10%) 	: Rp.427.5
+   ----------------------------------
+   TotalPayment 	: Rp.4702.5
+*/
\ No newline at end of file
diff --git a/SumDigits.js b/SumDigits.js
new file mode 100644
index 0000000..8da48bd
--- /dev/null
+++ b/SumDigits.js
@@ -0,0 +1,20 @@
+/**
+ * input 4 digit integer lalu hitung jumlahnya
+ */
+
+function sumDigit(n){
+   if(n>=10000){
+        return n+" harus lebih kecil dari 10000"
+   }
+   else if(isNaN(n)){
+       return n+" is not number, try again..."
+   }
+   else{
+       return parseInt(n.toString().charAt(0))+parseInt(n.toString().charAt(1))+parseInt(n.toString().charAt(2))+parseInt(n.toString().charAt(3))
+   }
+}
+
+console.log(sumDigit(1234)); //10
+console.log(sumDigit("1234"));//10
+console.log(sumDigit(12345));//12345 harus lebih kecil dari 10000
+console.log(sumDigit("a123"));//a123 is not number, try again...
\ No newline at end of file