{"data":{"site":{"siteMetadata":{"title":"lastrites2018","author":"lastrites2018","siteUrl":"https://lastrites2018.netlify.com","comment":{"disqusShortName":"","utterances":"lastrites2018/gatsby-first-blog"},"sponsor":{"buyMeACoffeeId":""}}},"markdownRemark":{"id":"92b44215-2e3b-5f36-b0ff-3f0fca61f8a0","excerpt":"메모이제이션 구현 실패 2.","html":"
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  1. 메모이제이션 구현 실패
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Write a function called \"computeSummationToN\".\n\nGiven a number, \"computeSummationToN\" returns the sum of sequential numbers leading up to the given number, beginning at 0.\n\nNotes:\n* If n = 4, it should calculate the sum of 1 + 2 + 3 + 4, and return 10.\n\nvar output = computeSummationToN(6);\nconsole.log(output); // --> 21\n\nlet computeSummationToN = (n) => {\n  // your code here\n  if (n <= 0) { return 0; }\n  let number = n -1;\n  return n + computeSummationToN(number);\n}\n\nvar output = computeSummationToN(6);\nconsole.log(output); // --> 21\n\nhttps://repl.it/student/submissions/3704928\n\n// 메모이제이션을 넣어서 구현하고 싶었는데 실패했다. 아직도 너무 부족하다.
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https://repl.it/student/submissions/3673320\nWrite a function called \"getElementOfArrayProperty\".\n\nGiven an object, a key, and a numerical index, \"getElementOfArrayProperty\" returns the value of the element at the given index of the array located within the given object at the given key.\n\nNotes:\n* If the array is empty, it should return undefined.\n* If the given index is out of range of the array located at the given key, it should return undefined.\n* If the property at the given key is not an array, it should return undefined.\n* If there is no property at the key, it should return undefined.\n\nvar obj = {\n key: ['Jamil', 'Albrey']\n};\nvar output = getElementOfArrayProperty(obj, 'key', 0);\nconsole.log(output); // --> 'Jamil'\n\n// 첫 풀이\nlet getElementOfArrayProperty = (obj, key, index) => {\n  // your code here\n  if (!obj.key || obj.key.length <=0) { return undefined;}\n  if (!obj.key[index])\n  { return undefined; }\n  if (!obj[key]) {\n    return undefined;\n  }\n\n  //???\n  return obj[key][index];\n\n}\n//error 내용\nShould_return_undefined_3\nError: Expected 'e' to be undefined.\n중간에\n\nif (typeof obj[key] !== 'object') {\n    return undefined;\n  } // 이거 넣으면 바로 통과한다. 왜?\n\nvar obj = {\n key: ['Jamil', 'Albrey']\n};\nvar output = getElementOfArrayProperty(obj, 'e', 'e');\nconsole.log(output); // --> 'Jamil'
","frontmatter":{"title":"wrong answer","date":"September 14, 2018"}}},"pageContext":{"isCreatedByStatefulCreatePages":false,"slug":"/til/20180914 - wrong answer/","previous":{"fields":{"slug":"/til/20180912 Demo Day - immersive 7/"},"frontmatter":{"title":"Immersive 7기의 데모데이를 보고 왔다","category":"TIL"}},"next":{"fields":{"slug":"/til/20180914 자바스크립트 자료 구조와 알고리즘 - 로이아니 그로네르/"},"frontmatter":{"title":"자바스크립트 자료 구조와 알고리즘 - 로이아니 그로네르","category":"TIL"}}}}