Something about ts

.gitignore

@@ -1,3 +1,2 @@
-solutions
-
-.DS_Store
+node_modules/
+dist/

package.json

@@ -8,5 +8,9 @@
     "exec": "node scripts/exec-script.js"
   },
   "author": "ming",
-  "license": "ISC"
-}
+  "license": "ISC",
+  "dependencies": {
+    "node-fetch": "^3.3.2",
+    "typescript": "^5.1.6"
+  }
+}

problems/p1-data-types/main.js

@@ -28,12 +28,13 @@ function swap(a, b) {
   var tmp = a;
   a = b;
   b = tmp;
+  return {a, b}
 }
 
 var x = 10;
 var y = 20;
-swap(x, y);
-console.log(x, y);
+const vv = swap(x, y);
+console.log(vv.a, vv.b);
 
 console.log('\n');
 

problems/p2-build-in-objects/main.js

@@ -62,6 +62,134 @@ console.log('quiz: ');
 //   { source: 3, target: 4 },
 //   { source: 4, target: 5 },
 // ];
-const array = [0, 1, 2, 3, 4, 5].reduce((result) => result, []);
+const array = [0, 1, 2, 3, 4, 5].reduce((result, item, index, arr) => {
+    console.log(result, item, index);
+    if (index < arr.length - 1) {
+        result.push({ source: index, target: index + 1 });
+        console.log(result)
+    }
+    return result;
+}, []);
+
+
+
+
+
+// const array = [0, 1, 2, 3, 4, 5].reduce((result, item, index, arr) => {
+//     if (index < arr.length - 1) {
+//         console.log(arr[0]);
+//         result.push({ source: item, target: arr[item + 1] });
+//     }
+//     return result;
+// }, []);
 
 console.log('array: ', array);
+
+// const array2 = [0, 1, 2, 3, 4, 5].filter((item, index, arr) => {
+
+//     return item % 2 == 0
+// })
+
+// console.log('array2: ', array2);
+
+// const arr = [1, 2, 3, 4, 5];
+// const reduceArrNoInitValue = arr.reduce((accumulator, currentValue) => {
+//     console.log(accumulator, currentValue);
+//     return accumulator + currentValue
+// });
+// console.log('reduceArrNoInitValue: ', reduceArrNoInitValue);
+
+
+// const reduceArrInitValue = arr.reduce((accumulator, currentValue) => {
+//     console.log(accumulator, currentValue);
+//     return accumulator + currentValue
+// }, 0);
+// console.log('redureduceArrInitValueceArr: ', reduceArrInitValue);
+
+// const arrMerge = [['a', 'b'], ['c', 'd'], ['e', 'f']];
+
+// const mergedArr = arrMerge.reduce((accumulator, currentValue) => {
+//     console.log(accumulator, currentValue);
+//     return accumulator.concat(currentValue)
+// })
+
+// console.log('mergedArr: ', mergedArr);
+
+// const arrCount = ['a', 'a', 'b', 'c', 'c', 'c', 'e'];
+// const reduceArr = arrCount.reduce((accumulator, currentValue) => {
+//     console.log(accumulator, currentValue);
+//     if (accumulator[currentValue]) {
+//         console.log('before', accumulator[currentValue]);
+//         accumulator[currentValue]++;
+//         console.log('after', accumulator[currentValue]);
+//     } else {
+//         accumulator[currentValue] = 1;
+//     }
+//     return accumulator;
+// }, {});
+// console.log(reduceArr); // { a: 2, b: 1, c: 3, e: 1 }
+
+// const average = arr => arr.reduce((p, c) => p + c, 0) / arr.length;
+// const calArray = [115, 26, 99]
+// const calArr = calArray.reduce((accumulator, currentValue, index, arr) => {
+//     console.log(accumulator, currentValue, index, arr);
+//     // implement reduce function to calculate min, max, average
+//     const result = { max: Math.max(...arr), min: Math.min(...arr), average: average(currentValue, arr) }
+//     console.log(result)
+//     return result
+// }, {})
+// console.log(calArr);
+
+
+const numbers = [1, 2, 3, 4, 5];
+
+const result = numbers.reduce((acc, curr, index, array) => {
+    // Calculate the maximum
+    acc.max = Math.max(acc.max || curr, curr);
+
+    // Calculate the minimum
+    acc.min = Math.min(acc.min || curr, curr);
+
+    // Calculate the sum
+    acc.sum = (acc.sum || 0) + curr;
+
+
+    // Calculate the average
+    // only when last element is reached, then we can calculate the average
+    if (index === array.length - 1) {
+        acc.average = acc.sum / array.length;
+    }
+    // console.log(acc)
+    return acc;
+});
+
+console.log(result);
+
+
+
+// const numbers = [1, 2, 3, 4, 5];
+
+// const result = numbers.reduce((acc, curr, index, array) => {
+//     if (index === 0) {
+//         // set init value
+//         acc.max = curr;
+//         acc.min = curr;
+//         acc.sum = curr;
+//     } else {
+//         // Calculate the maximum
+//         acc.max = Math.max(acc.max, curr);
+
+//         // Calculate the minimum
+//         acc.min = Math.min(acc.min, curr);
+
+//         // Calculate the sum
+//         acc.sum += curr;
+//     }
+//     // Calculate the average
+//     if (index === array.length - 1) {
+//         acc.average = acc.sum / array.length;
+//     }
+//     return acc;
+// }, {});
+
+// console.log(result);

problems/p3-function/main.js

@@ -36,10 +36,15 @@ const arr = [1, 2, 3].map((item) => item * 2);
  */
 function customMap(array, callback) {
   const newArray = [];
+  for (let i = 0; i < array.length; i++) {
+    newArray.push(callback(array[i]));
+  }
   return newArray;
 }
 
-const newArr = customMap([1, 2, 3], (item) => item * 2);
+const newArr = customMap([1, 2, 3], (item) => {
+  return item * 2
+});
 
 console.log('arr: ', arr);
 console.log('newArr: ', newArr);
@@ -52,17 +57,29 @@ function returnFunction() {
   };
 };
 
-const curryFunc = (args) => (callback) => {
-  return callback(args[0], args[1]);
+const curryFunc = (args) => {
+  return (callback) => {
+    return callback(args[0], args[1]);
+  }
 };
 
 const curriedFunc = curryFunc([1, 2]);
-let plus;
-let minus;
-let multiply;
-let divide;
-
-console.log('plus: ', plus);
-console.log('minus: ', minus);
-console.log('multiply: ', multiply);
-console.log('divide: ', divide);
+let plus = (a, b) => {
+  return  a+b 
+};
+let minus = (a,b) => {
+  return a-b
+};
+let multiply = (a, b) => {
+  return a*b
+};
+let divide = (a,b) => {
+  return a/b
+};
+
+console.log('plus: ', curryFunc([1,2])(plus));
+console.log('minus: ',  curryFunc([1,2])(minus));
+console.log('multiply: ',  curryFunc([1,2])(multiply));
+console.log('divide: ', curryFunc([1,2])(divide));
+
+