2회차 스터디 후 src/1week 리팩터링하기

src/1week/01.js

@@ -1,7 +1,7 @@
-var x = 2;
+var x =2
 
-function lineFunction() {
-  return 2 * x + 3;
+function lineFunction(param = x) {
+  return 2 * param + 3;
 }
 
 exports.lineFunction = lineFunction;

src/1week/02.js

@@ -1,11 +1,8 @@
-function accumulate(arr) {
-  let accumulator = 0;
+const sum = (a,b) => a+b 
 
-  for (let i = 0; i < arr.length; i++) {
-    accumulator += arr[i];
-  }
-
-  return accumulator;
+function accumulate(arr,combiner = sum, initialVal = 0) {
+
+  return arr.reduce(combiner, initialVal);
 }
 
 exports.accumulate = accumulate;

src/1week/03.js

@@ -1,15 +1,10 @@
-function multiDimensionalAccumulate(multiDimensionalArr) {
-  let accumulator = 0;
+const { accumulate } = require('./02.js');
 
-  for (let i = 0; i < multiDimensionalArr.length; i++) {
-    for (let j = 0; j < multiDimensionalArr[i].length; j++) {
-      if (j < i) {
-        accumulator += multiDimensionalArr[i][j];
-      }
-    }
-  }
+const  arraySlice= (arr,startIdx=0, EndIdx) => arr.slice(startIdx, EndIdx)
+const multiArrMapAndFlatten = (multiArr, mapper) => multiArr.map(mapper).flat()
 
-  return accumulator;
+function multiDimensionalAccumulate(multiDimensionalArr) {
+  return accumulate(multiArrMapAndFlatten(multiDimensionalArr,arraySlice))
 }
 
 exports.multiDimensionalAccumulate = multiDimensionalAccumulate;

src/1week/04.js

@@ -1,15 +1,15 @@
-function convertToConditionalUpperCase(words) {
-  let capitalized = [];
+function isLongerThan(word, length) {
+  return word.length > length;
+}
 
-  for (let i = 0; i < words.length; i++) {
-    if (words[i].length > 5) {
-      capitalized.push(words[i].toUpperCase());
-    } else {
-      capitalized.push(words[i].toLowerCase());
-    }
-  }
+function makeCapitalWithCondition(word, conditionSatisfied) {
+  return conditionSatisfied ? word.toUpperCase() : word.toLowerCase();
+}
 
-  return capitalized;
+function convertToConditionalUpperCase(words) {
+  return words.map((word) =>
+    makeCapitalWithCondition(word, isLongerThan(word, 5))
+  );
 }
 
 exports.convertToConditionalUpperCase = convertToConditionalUpperCase;

src/1week/05.js

@@ -1,5 +1,41 @@
-function deepCopy(obj) {
-  return obj;
+function deepCopy(original) {
+  const copy = {};
+
+  for (const [key, value] of Object.entries(original)) {
+    if (original.hasOwnProperty(key)) {
+      if (typeof value !== 'object' || value === null) {
+        copy[key] = value;
+      }
+      // Symbol 처리 확인
+       else if (value instanceof Date) {
+      copy[key] = new Date(value);
+      } else if (value instanceof RegExp) {
+        copy[key] = new RegExp(value);
+      } else if (Array.isArray(value)) {
+        copy[key] = value.map(deepCopy); 
+      } else if (value instanceof Map) {
+        const copiedMap = new Map();
+        for (const [mapKey, mapValue] of value.entries()) {
+          copiedMap.set(mapKey, deepCopy(mapValue));
+        }
+        copy[key] = copiedMap;
+      } else if (value instanceof Set) {
+        const copiedSet = new Set();
+        for (const setValue of value) {
+          copiedSet.add(deepCopy(setValue)); 
+        }
+        copy[key] = copiedSet;
+      } else if (typeof value === 'function') {
+        copy[key] = function() {
+          return value.apply(this, arguments);
+        };
+      } else {
+        copy[key] = deepCopy(value);
+      }
+    }
+  }
+
+  return copy;
 }
 
 exports.deepCopy = deepCopy;