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/HowManyElapsedTime.js b/HowManyElapsedTime.js
new file mode 100644
index 0000000..65ec661
--- /dev/null
+++ b/HowManyElapsedTime.js
@@ -0,0 +1,19 @@
+/** berapa banyak tahun kabisat antara tahun1 ke tahun2 */
+
+function howManyKabisat(year1,year2){
+    while(year1<year2){
+        if(isKabisat(year1)){
+            console.log(year1);
+        }
+        year1++;
+    }
+}
+
+function isKabisat(year){
+    let checkLeap=year;
+    if(checkLeap%4==0 ){
+        console.log(checkLeap);
+    }
+}
+
+console.log(howManyKabisat(1997,2021));
\ No newline at end of file
diff --git a/Permutation.js b/Permutation.js
new file mode 100644
index 0000000..28d3f83
--- /dev/null
+++ b/Permutation.js
@@ -0,0 +1,21 @@
+const checkPermute = function(stringOne, stringTwo) {
+    // if different lengths, return false
+    if(stringOne.split("").length!=stringTwo.split("").length){
+        return false;
+    }
+    // else sort and compare 
+    // (doesnt matter how it's sorted, as long as it's sorted the same way)
+    else{
+        if(stringOne.split("").sort().join()!=stringTwo.split("").sort().join()){
+            return false;
+        }
+        else{
+            return true;
+        }
+    }
+  };
+  
+  console.log(checkPermute('aba', 'aab'))//true;
+  console.log(checkPermute('aba', 'aaba'))//false;
+  console.log(checkPermute('aba', 'aa'))//false;
+
diff --git a/PrimeNumber.js b/PrimeNumber.js
new file mode 100644
index 0000000..5b39c42
--- /dev/null
+++ b/PrimeNumber.js
@@ -0,0 +1,35 @@
+
+function showPrimeNumber(n){
+    isPrime(n);
+}
+
+function isPrime(n){
+    for (let i = 2; i <= n; i++) {
+        let flag = 0;
+    
+        // looping through 2 to user input number
+        for (let j = 2; j < i; j++) {
+            if (i % j == 0) {
+                flag = 1;
+                break;
+            }
+        }
+    
+        // if number greater than 1 and not divisible by other numbers
+        if (i > 1 && flag == 0) {
+            console.log(i);
+        }
+    }
+}
+
+console.log(showPrimeNumber(100));
+/**
+
+2	3	5	7	11
+13	17	19	23	29
+31	37	41	43	47
+53	59	61	67	71
+73	79	83	89	97
+
+ */
+
diff --git a/Segitiga.js b/Segitiga.js
new file mode 100644
index 0000000..27e6585
--- /dev/null
+++ b/Segitiga.js
@@ -0,0 +1,31 @@
+/** buat segitiga  */ 
+let triangle1='';
+for (let i = 1; i < 5; i++) {
+    for (let j = 1; j < 6-i; j++) {
+        triangle1+=j+" ";
+    } 
+    console.log(triangle1+"\n");
+    triangle1='';
+} 
+// output 
+// 1 2 3 4 
+// 1 2 3 
+// 1 2 
+// 1 
+
+
+let triangle2='';
+for (let i = 0; i < 6; i++) {
+    for (let j = 5-i; j > 0; j--) {
+        triangle2+=j+" ";
+    } 
+    console.log(triangle2+"\n");
+    triangle2='';
+}  
+
+// output
+// 5 4 3 2 1  
+// 4 3 2 1  
+// 3 2 1
+// 2 1  
+// 1  
diff --git a/StringToDate.js b/StringToDate.js
new file mode 100644
index 0000000..6d92a1d
--- /dev/null
+++ b/StringToDate.js
@@ -0,0 +1,15 @@
+/** ubah value string ke date 
+ *  gunakan split
+ *  inputan s = bulan/hari/tahun
+*/
+function strToDate(s){
+        for(let i=0;i<3;i++){
+                if(isNaN(s.split("/")[i])){
+                        return s+" bad format date";
+                }     
+        }
+        return new Date(s);
+}
+
+console.log(strToDate('12/30/2021'));//Thu Dec 30 2021 00:00:00 GMT+0700 (Western Indonesia Time)
+console.log(strToDate('12/aa/bb')); //12/aa/bb bad format date
diff --git a/isArrayEqual.js b/isArrayEqual.js
new file mode 100644
index 0000000..3e88281
--- /dev/null
+++ b/isArrayEqual.js
@@ -0,0 +1,14 @@
+function isArraysEqual(arrayA, arrayB) {
+    for(let i=0;i<4;i++){
+        if(arrayA[i]!=arrayB[i]){
+            return false;
+        }
+    }
+    return true;
+}
+
+const fruitNamesA = ['rambutan', 'durian', 'jeruk', 'nangka'];
+const fruitNamesB = ['rambutan', 'durian', 'jeruk', 'nangka'];
+const fruitNamesC = ['anggur', 'apel', 'mangga', 'alpukat'];
+console.log(isArraysEqual(fruitNamesA, fruitNamesB)); // true
+console.log(isArraysEqual(fruitNamesA, fruitNamesC)); // false
\ No newline at end of file
diff --git a/isCharsUnique.js b/isCharsUnique.js
new file mode 100644
index 0000000..f5a3147
--- /dev/null
+++ b/isCharsUnique.js
@@ -0,0 +1,13 @@
+function isCharsUnique(string){
+    for(let i=0;i<string.length;i++){
+        for(let j=1+i;j<string.length;j++){
+            if(string[i]==string[j]){
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+console.log(isCharsUnique('abcdefg'));//true
+console.log(isCharsUnique('abcdefga'));//false
\ No newline at end of file
diff --git a/maxlength.js b/maxlength.js
new file mode 100644
index 0000000..aa52be7
--- /dev/null
+++ b/maxlength.js
@@ -0,0 +1,15 @@
+function maxWordLength(params) {
+    let maxArr=params.split(" ");
+    let numArr=[];
+    
+    for(let i=0;i<maxArr.length;i++){
+        numArr.push(maxArr[i].length);
+    }
+
+    const max = Math.max(...numArr);
+    const indexMax=numArr.indexOf(max);
+    return maxArr[indexMax];
+}
+
+console.log(maxWordLength("aku suka bootcamp sentul city"));//bootcamp
+
diff --git a/palindrome.js b/palindrome.js
new file mode 100644
index 0000000..e2be754
--- /dev/null
+++ b/palindrome.js
@@ -0,0 +1,11 @@
+function isPalindrome(word){
+    let wordArr=word.split("");
+    let reverseWord=wordArr.reverse().join();
+    for(let i=0;i<=wordArr.length;i++){
+        if(wordArr[i]==reverseWord[i]){
+            return true;
+        }
+    }
+}
+
+console.log(isPalindrome('kasur ini rUsak'));//true