\ub9ac\uc561\ud2b8(React)\ub294 \uc0ac\uc6a9\uc790 \uc778\ud130\ud398\uc774\uc2a4\ub97c \uad6c\uc131\ud558\uae30 \uc704\ud55c \ub77c\uc774\ube0c\ub7ec\ub9ac\ub85c\uc11c, \ub2e8\uc77c \ud398\uc774\uc9c0 \uc560\ud50c\ub9ac\ucf00\uc774\uc158(SPA)\uc744 \uc27d\uac8c \uad6c\ucd95\ud560 \uc218 \uc788\uac8c \ud574\uc90d\ub2c8\ub2e4. \ub9ac\uc561\ud2b8\uc758 \uc8fc\uc694 \uac1c\ub150 \uc911 \ud558\ub098\ub294 \ucef4\ud3ec\ub10c\ud2b8\uc785\ub2c8\ub2e4. \uc774 \ucef4\ud3ec\ub10c\ud2b8\ub294 UI\uc758 \ub450\ub1cc \uc5ed\ud560\uc744 \ud558\uba70, \uac01 \ucef4\ud3ec\ub10c\ud2b8\ub294 \uc790\uc2e0\uc758 \uc0c1\ud0dc(state)\uc640 \uc18d\uc131(props)\uc744 \uad00\ub9ac\ud569\ub2c8\ub2e4. \uc774 \uae00\uc5d0\uc11c\ub294 \ud6a8\uacfc \ucc98\ub9ac\uc5d0 \ub110\ub9ac \uc0ac\uc6a9\ub418\ub294 \uc704 \uc608\uc81c\uc5d0\uc11c \uc758\uc874\uc131 \ubc30\uc5f4\uc744 \uc124\uc815\ud558\uba74 \ud2b9\uc815 \uac12\uc774 \ubcc0\uacbd\ub420 \ub54c \uc774 \uacbd\uc6b0, \ubc84\ud2bc\uc744 \ud074\ub9ad\ud558\uc5ec \uce74\uc6b4\ud2b8\ub97c \uc99d\uac00\uc2dc\ud0a4\uba74 \uc81c\ubaa9\uc774 \ubcc0\uacbd\ub429\ub2c8\ub2e4.<\/p>\n \ub9ac\uc561\ud2b8\uc5d0\uc11c API\ub97c \ud1b5\ud574 \ub370\uc774\ud130\ub97c \uc694\uccad\ud560 \ub54c\ub294 \uc77c\ubc18\uc801\uc73c\ub85c \uc704 \uc608\uc81c\uc5d0\uc11c\ub294 API \uc694\uccad\uc744 \ud1b5\ud574 \ub370\uc774\ud130\ub97c \uac00\uc838\uc628 \ud6c4, \ub85c\ub529 \uc0c1\ud0dc\ub97c \uad00\ub9ac\ud558\uace0, \uc624\ub958 \ucc98\ub9ac\ub3c4 \uc218\ud589\ud569\ub2c8\ub2e4. \uc774\uc81c API \uc5f0\ub3d9\uc758 \uc2e4\uc81c \uc608\uc81c\ub97c \ub9cc\ub4e4\uc5b4 \ubcf4\uaca0\uc2b5\ub2c8\ub2e4. JSONPlaceholder\ub77c\ub294 \ubb34\ub8cc API\ub97c \uc0ac\uc6a9\ud558\uc5ec \uc0ac\uc6a9\uc790 \ubaa9\ub85d\uc744 \uac00\uc838\uc624\ub294 \uac04\ub2e8\ud55c \uc560\ud50c\ub9ac\ucf00\uc774\uc158\uc744 \ub9cc\ub4e4\uc5b4 \ubcf4\uaca0\uc2b5\ub2c8\ub2e4.<\/p>\n \uc704\uc758 \ub354 \ub098\uc544\uac00 \ub9ac\uc561\ud2b8 \ucffc\ub9ac(React Query) \uac19\uc740 \ub77c\uc774\ube0c\ub7ec\ub9ac\ub97c \uc0ac\uc6a9\ud558\uc5ec API \ud638\ucd9c \ubc0f \ub370\uc774\ud130 \uce90\uc2f1\uc744 \uad00\ub9ac\ud558\uba74 \ud6e8\uc52c \ub354 \ud6a8\uc728\uc801\uc778 \uc791\uc5c5\uc774 \uac00\ub2a5\ud569\ub2c8\ub2e4. \ud558\uc9c0\ub9cc \uc774 \uae00\uc5d0\uc11c\ub294 \uac00\uc7a5 \uac04\ub2e8\ud558\uace0 \uae30\ubcf8\uc801\uc778 \ubc29\uc2dd\uc73c\ub85c API \uc5f0\ub3d9\uc744 \ub2e4\ub8e8\uc5c8\uc2b5\ub2c8\ub2e4. \uc55e\uc73c\ub85c \ub354 \ubc1c\uc804\ub41c \uae30\uc220\uacfc \ud328\ud134\uc744 \ubc30\uc6b0\uace0 \uc801\uc6a9\ud574 \ubcf4\uc2dc\uae30 \ubc14\ub78d\ub2c8\ub2e4.<\/p>\n <\/body><\/p>\n","protected":false},"excerpt":{"rendered":"useEffect<\/code> \ud6c5\uacfc \ube44\ub3d9\uae30 \uc791\uc5c5\uc5d0 \ub300\ud574 \uc54c\uc544\ubcf4\uace0, \uc774\ub97c \ud65c\uc6a9\ud558\uc5ec API\ub85c\ubd80\ud130 \ub370\uc774\ud130\ub97c \uc694\uccad\ud558\ub294 \ubc29\ubc95\uc744 \uc2ec\ub3c4 \uae4a\uac8c \uc124\uba85\ud558\uaca0\uc2b5\ub2c8\ub2e4.<\/p>\n1. useEffect \ud6c5 \uc18c\uac1c<\/h3>\n
useEffect<\/code>\ub294 \ucef4\ud3ec\ub10c\ud2b8\uc758 \uc0dd\uba85\uc8fc\uae30 \uc5d0\uc11c \uc0ac\uc774\ub4dc \uc774\ud399\ud2b8\ub97c \ucc98\ub9ac\ud558\uae30 \uc704\ud55c \ud6c5\uc785\ub2c8\ub2e4. \uc8fc\ub85c \ub2e4\uc74c\uacfc \uac19\uc740 \uacbd\uc6b0\uc5d0 \uc0ac\uc6a9\ub429\ub2c8\ub2e4:<\/p>\n\n
1.1. \uae30\ubcf8 \uc0ac\uc6a9\ubc95<\/h4>\n
useEffect<\/code>\ub294 \ub450 \uac1c\uc758 \uc778\uc790\ub97c \ubc1b\uc2b5\ub2c8\ub2e4: \uccab \ubc88\uc9f8 \uc778\uc790\ub294 \uc0ac\uc774\ub4dc \uc774\ud399\ud2b8\ub97c \ubc1c\uc0dd\uc2dc\ud0a4\ub294 \ud568\uc218\uc774\uace0, \ub450 \ubc88\uc9f8 \uc778\uc790\ub294 \uc758\uc874\uc131 \ubc30\uc5f4\uc785\ub2c8\ub2e4. \uc758\uc874\uc131 \ubc30\uc5f4\uc5d0 \uc9c0\uc815\ub41c \uac12\uc774 \ubcc0\uacbd\ub420 \ub54c\ub9c8\ub2e4 \ud6a8\uacfc\uac00 \ub2e4\uc2dc \uc2e4\ud589 \ub429\ub2c8\ub2e4.<\/p>\nimport { useEffect } from 'react';\n\nfunction MyComponent() {\n useEffect(() => {\n \/\/ \ud6a8\uacfc\ub97c \ucc98\ub9ac\ud558\ub294 \ucf54\ub4dc\n document.title = 'My Component Loaded';\n\n \/\/ \uc815\ub9ac(clean up) \ud568\uc218\n return () => {\n document.title = 'React App';\n };\n }, []); \/\/ \ube48 \ubc30\uc5f4\uc740 \ucef4\ud3ec\ub10c\ud2b8\uac00 \ub9c8\uc6b4\ud2b8\ub420 \ub54c\ub9cc \uc2e4\ud589\ub428\n\n return <div>\uc548\ub155\ud558\uc138\uc694, \ub9ac\uc561\ud2b8 \ucef4\ud3ec\ub10c\ud2b8!<\/div>;\n}<\/code><\/pre>\nuseEffect<\/code>\ub294 \ucef4\ud3ec\ub10c\ud2b8\uac00 \ucc98\uc74c \ub80c\ub354\ub9c1\ub420 \ub54c \ud55c \ubc88\ub9cc \uc2e4\ud589\ub429\ub2c8\ub2e4. \uadf8\ub9ac\uace0 \ucef4\ud3ec\ub10c\ud2b8\uac00 \uc5b8\ub9c8\uc6b4\ud2b8\ub420 \ub54c \uc81c\ubaa9\uc744 \uc6d0\ub798 \uc0c1\ud0dc\ub85c \ub3cc\ub824 \ub193\uae30 \uc704\ud574 \uc815\ub9ac(clean up) \ud568\uc218\ub97c \ubc18\ud658\ud569\ub2c8\ub2e4.<\/p>\n1.2. \uc758\uc874\uc131 \ubc30\uc5f4\uc758 \uc911\uc694\uc131<\/h4>\n
useEffect<\/code>\uac00 \uc7ac\uc2e4\ud589\ub429\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uc5b4, \ub2e4\uc74c\uacfc \uac19\uc774 count<\/code>\ub77c\ub294 \uc0c1\ud0dc \uac12\uc744 \uc0ac\uc6a9\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4:<\/p>\nimport React, { useState, useEffect } from 'react';\n\nfunction Counter() {\n const [count, setCount] = useState(0);\n\n useEffect(() => {\n document.title = `\uce74\uc6b4\ud2b8: ${count}`;\n }, [count]); \/\/ count\uac00 \ubcc0\uacbd\ub420 \ub54c\ub9c8\ub2e4 \uc2e4\ud589\ub428\n\n return (\n <div>\n <p>\ud604\uc7ac \uce74\uc6b4\ud2b8: {count}<\/p>\n <button onClick={() => setCount(count + 1)}>\uce74\uc6b4\ud2b8 \uc99d\uac00<\/button>\n <\/div>\n );\n}<\/code><\/pre>\n2. \ube44\ub3d9\uae30 \ub370\uc774\ud130 \uc694\uccad<\/h3>\n
fetch<\/code> API\ub97c \uc0ac\uc6a9\ud569\ub2c8\ub2e4. \ube44\ub3d9\uae30 \uc791\uc5c5\uc744 \uc218\ud589\ud558\uae30 \uc704\ud574 useEffect<\/code>\uc640 \ud568\uaed8 async\/await<\/code> \ud328\ud134\uc744 \uc0ac\uc6a9\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ub2e4\uc74c\uc740 \ub370\uc774\ud130\ub97c API\ub85c\ubd80\ud130 fetch\ud558\ub294 \uac04\ub2e8\ud55c \uc608\uc81c\uc785\ub2c8\ub2e4.<\/p>\nimport React, { useState, useEffect } from 'react';\n\nfunction DataFetchingComponent() {\n const [data, setData] = useState(null);\n const [loading, setLoading] = useState(true);\n const [error, setError] = useState(null);\n\n useEffect(() => {\n const fetchData = async () => {\n try {\n const response = await fetch('https:\/\/api.example.com\/data');\n if (!response.ok) {\n throw new Error('\ub124\ud2b8\uc6cc\ud06c \uc751\ub2f5\uc5d0 \ubb38\uc81c\uac00 \uc788\uc2b5\ub2c8\ub2e4.');\n }\n const result = await response.json();\n setData(result);\n } catch (error) {\n setError(error);\n } finally {\n setLoading(false);\n }\n };\n\n fetchData(); \/\/ \ube44\ub3d9\uae30 \ud568\uc218 \ud638\ucd9c\n }, []); \/\/ \ube48 \ubc30\uc5f4\uc740 \ucef4\ud3ec\ub10c\ud2b8\uac00 \ub9c8\uc6b4\ud2b8\ub420 \ub54c\ub9cc \uc2e4\ud589\ub428\n\n if (loading) return <p>\ub85c\ub529 \uc911...<\/p>;\n if (error) return <p>\uc624\ub958: {error.message}<\/p>;\n return <pre>{JSON.stringify(data, null, 2)}<\/pre>;\n}<\/code><\/pre>\nuseEffect<\/code> \ub0b4\ubd80\uc5d0\uc11c \ube44\ub3d9\uae30 \ud568\uc218\ub97c \uc120\uc5b8\ud558\uace0 \ud638\ucd9c\ud558\ub294 \ubc29\uc2dd\uc73c\ub85c \uc9c4\ud589\ub429\ub2c8\ub2e4.<\/p>\n3. API \uc5f0\ub3d9 \uc2e4\uc2b5<\/h3>\n
import React, { useState, useEffect } from 'react';\n\nfunction UserList() {\n const [users, setUsers] = useState([]);\n const [loading, setLoading] = useState(true);\n const [error, setError] = useState(null);\n\n useEffect(() => {\n const fetchUsers = async () => {\n setLoading(true);\n try {\n const response = await fetch('https:\/\/jsonplaceholder.typicode.com\/users');\n if (!response.ok) throw new Error('\ub124\ud2b8\uc6cc\ud06c \uc751\ub2f5\uc5d0 \ubb38\uc81c\uac00 \uc788\uc2b5\ub2c8\ub2e4.');\n const data = await response.json();\n setUsers(data);\n } catch (error) {\n setError(error);\n } finally {\n setLoading(false);\n }\n };\n\n fetchUsers();\n }, []);\n\n if (loading) return <p>\ub85c\ub529 \uc911...<\/p>;\n if (error) return <p>\uc624\ub958: {error.message}<\/p>;\n\n return (\n <ul>\n {users.map(user => (\n <li key={user.id}>{user.name} ({user.email})<\/li>\n ))}\n <\/ul>\n );\n}<\/code><\/pre>\nUserList<\/code> \ucef4\ud3ec\ub10c\ud2b8\ub294 \uc0ac\uc6a9\uc790\uc758 \ubaa9\ub85d\uc744 \uac00\uc838\uc640 \ud654\uba74\uc5d0 \ud45c\uc2dc\ud569\ub2c8\ub2e4. \ub370\uc774\ud130\uac00 \ub85c\ub529 \uc911\uc77c \ub54c\ub294 \ub85c\ub529 \uba54\uc2dc\uc9c0\ub97c \ubcf4\uc5ec\uc8fc\uace0, \uc624\ub958\uac00 \ubc1c\uc0dd\ud558\uba74 \uc624\ub958 \uba54\uc2dc\uc9c0\ub97c \ud45c\uc2dc\ud569\ub2c8\ub2e4.<\/p>\n4. \uc815\ub9ac<\/h3>\n
useEffect<\/code> \ud6c5\uc744 \ud65c\uc6a9\ud558\uc5ec \ucef4\ud3ec\ub10c\ud2b8\uc758 \uc0dd\uba85 \uc8fc\uae30\uc5d0\uc11c \uc0ac\uc774\ub4dc \uc774\ud399\ud2b8\ub97c \ucc98\ub9ac\ud558\uace0, \ube44\ub3d9\uae30 \uc791\uc5c5\uc744 \ud1b5\ud574 \uc678\ubd80 API\uc640 \uc5f0\ub3d9\ud558\ub294 \uacfc\uc815\uc744 \uc0b4\ud3b4\ubcf4\uc558\uc2b5\ub2c8\ub2e4. \uc774 \ud328\ud134\uc740 \ub9ac\uc561\ud2b8 \uc560\ud50c\ub9ac\ucf00\uc774\uc158\uc5d0\uc11c \ub370\uc774\ud130 fetching \ubc0f \uad00\ub9ac\uc5d0\uc11c \ud544\uc218\uc801\uc778 \ubd80\ubd84\uc785\ub2c8\ub2e4. \ub2e4\uc591\ud55c API\ub97c \ud65c\uc6a9\ud558\uc5ec \ub370\uc774\ud130\uc758 \uc0c1\ud0dc\ub97c \uad00\ub9ac\ud558\uace0 \uc0ac\uc6a9\uc790\uc5d0\uac8c \ub354\uc6b1 \ud48d\ubd80\ud55c \uacbd\ud5d8\uc744 \uc81c\uacf5\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n