#phpcon 良いコードを書けるようになるコツは「エラーを気にする」 〜プログラマにとってエラーとは何なのか〜

PHP Conference Japan 2023での発表資料です。
https://fortee.jp/phpcon-2023/proposal/b2568517-f8ae-4ae7-85f4-89adc624fcda

1. 
 PHP Conference 2023 Hideki Kinjyo GitHub: o0h / Twitter: @o0h_ 
 
 [ൃද൛]
2. ࣗݾ঺հ / GitHub: @o0h / X: @o0h_ FW CakePHP  
3. ⏳estimate: 0 1 /25
4. ⏳estimate: 0 1 /25
5. 
 ⏳estimate: 0 1 /25
6. ҧ͏ʂʂ
   Τϥʔ͸ఢ͡Όͳ͍ɺ
   ༑ୡͳΜͩʂʂ ⏳estimate: 1 /25
7. ͜ΜͳࣄΛ࿩͍͖ͯ͠·͢ PHP  ⏳estimate: 1 2 /25 ˒খ͞ͳએ఻ίʔφʔ˒
8. ͜Μͳ΋ͷΛ࣋ͬͯؼͬͯ΋Β͍͍ͨ PHP  ⏳estimate: 1 2 /25
9. ͓͠ͳ͕͖ 1. 2. PHP 3. 4. PRO 5. PHP  ⏳estimate: 1 2 /25
10. §1
11. ϓϩάϥϛϯάݴޠ͸ͳͥʮΤϥʔʯΛݴͬͯ͘Δͷʁ =  ⏳estimate: 1 2 /25
12. PHP Software Developers 
 
 
 ⏳estimate: 1 2 /25
13. PHP Software Developers 
 
 
 ૝͍ ⏳estimate: 2 /25
14. ⏳estimate: 2 /25
15. ⏳estimate: 2 /25
16. Τϥʔͷ͋Δੈքɺͳ͍ੈքɾɾɾͲ͕ͬͪྑ͍Ͱ͔͢ʁ : 31 : : :  ⏳estimate: 2~3 /25
17. Τϥʔͷ͋Δੈքɺͳ͍ੈքɾɾɾͲ͕ͬͪྑ͍Ͱ͔͢ʁ (= ) => => =>  ⏳estimate: 2~3 /25
18. Τϥʔͷ͋Δੈքͷํ͕ɺ༏͍͠ੈք 2  ⏳estimate: 2~3 /25
19. PHP 👀 ⏳estimate: 2~3 /25
20. ྫ͑͹sprintf()ͷྫ (% ) switch  src: IUUQTHJUIVCDPNQIQQIQTSDCMPCQIQFYUTUBOEBSEGPSNBUUFE@QSJOUD--
    
21. ྫ͑͹sprintf()ͷྫ case (default )  ⏳estimate: 3 /25
22. ྫ͑͹sprintf()ͷྫ  src: IUUQTHJUIVCDPNQIQQIQTSDCMPCQIQFYUTUBOEBSEGPSNBUUFE@QSJOUD--
    (% )
23. 
 ⏳estimate: 3 /25
24. Τϥʔɺ͑Βʙ͍👏 : :  ⏳estimate: 3~4 /25
25. §2 PHP
26. §2 PHP .1 .2 PHP
27. Τϥʔʹ͸ʮఔ౓ʯ͕͋Δͧ ( ) 
  ⏳estimate: 4 /25
28. [ࣸਅ] (্) ৅ҹ ενʔϜࣜՃ࣪ث EE-RQ35ܕ/EE-RQ50ܕ औѻઆ໌ॻ (Լ) ΞΠϦεΦʔϠϚ ਅۭอଘϑʔυγʔϥʔ VPF-385T औѻઆ໌ॻ ࢀߟ: Ոి඼Λ҆શʹ࢖͏ͨΊͷϚʔΫʛҰൠࡒஂ๏ਓՈి੡඼ڠձ https://aeha.or.jp/safety/mark/index.html ৘ใͷ෼ྨͷྫ: ՈిͷϚχϡΞϧ : : 
29. ৘ใͷ෼ྨͷྫ: ՈిͷϚχϡΞϧ  [ࣸਅ] ৅ҹ ενʔϜࣜՃ࣪ث EE-RQ35ܕ/EE-RQ50ܕ औѻઆ໌ॻ
30. ৘ใ͕෼ྨ͞Ε͍ͯΔͱศརͰ͢Ͷʂ  ⏳estimate: 5 /25
31. ͲΜͳʮఔ౓ʯ͕͋Δʁ : : ( ): :  ⏳estimate: 5~6 /25
32. §2 PHP .1 .2 PHP ⏳estimate: 5~6 /25
33. PHPʹ͓͚ΔΤϥʔఆ਺(ΤϥʔϨϕϧ)  IUUQTXXXQIQOFUNBOVBMKBFSSPSGVODDPOTUBOUTQIQ
34. PHPͷΤϥʔܥ౷ 
35. PHPͷΤϥʔܥ౷  ͦΕͧΕɺ఻͑Α͏ͱ͍ͯ͠Δҙਤ͕ҧͬͨΓ 
 ΋ͨΒ݁͢Ռ͕ҧ͏Μͩͳʙ ۠ผ͕͋ΔΜͩͳʙ ⏳estimate: 6 /25
36. PHPͷΤϥʔͨͪʙ͜Ε͚ͩ͸֮͑Α͏ʙ E_ERROR => [ ] PHP E_WARNING => [ ] PHP E_NOTICE => [ ] PHP  ⏳estimate: 6 /25
37. E_ERROR / ॏେ (Throwable)  ⏳estimate: 6~7 /25
38. E_WARNING / ܯࠂ ( ) ( ) URL 
39. E_NOTICE / ஫ҙ 
40. §3
41. §3 .1 .2 ⏳estimate: 7 /25
42. ྑ͘ͳͦ͞͏ͳίʔυͱ͍͏ͷ͕͋Δ  ⏳estimate: 7 /25
43. ᐆດ͞ʹ͍ͭͯ: shin1x1͞Μʮ੍໿ͷྗʯ  https://speakerdeck.com/shin1x1/restricting-states ⏳estimate: 7~8 /25
44. ᐆດ͞ʹ͍ͭͯ: shin1x1͞Μʮ੍໿ͷྗʯ  https://speakerdeck.com/shin1x1/restricting-states ⏳estimate: 7~8 /25
45. ᐆດ͞ʹ͍ͭͯ: shin1x1͞Μʮ੍໿ͷྗʯ  https://speakerdeck.com/shin1x1/restricting-states ⏳estimate: 7~8 /25
46. ᐆດ͞ʹ͍ͭͯ: shin1x1͞Μʮ੍໿ͷྗʯ  https://speakerdeck.com/shin1x1/restricting-states ⏳estimate: 8 /25
47. ᐆດ͞ʹ͍ͭͯ: t-wada͞Μͷʮ༧๷ʹউΔ๷ޚͳ͠ʯ  https://speakerdeck.com/twada/growing-reliable-code-phperkaigi-2022 ⏳estimate: 8 /25
48. ᐆດ͞ʹ͍ͭͯ: t-wada͞Μͷʮ༧๷ʹউΔ๷ޚͳ͠ʯ  https://speakerdeck.com/twada/growing-reliable-code-phperkaigi-2022 ⏳estimate: 8 /25
49. ྑ͘ͳ͍ίʔυ͕͜͏ͯ͠ੜ·ΕΔͧ ( )  ⏳estimate: 8~9 /25
50. ΤϥʔͱՄೳੑ ❌ 
 ⭕  ⏳estimate: 8~9 /25
51. ͜ͷίʔυ͸ո͍͕͠ɾɾɾ  ⏳estimate: 9 /25
52. ͜ͷίʔυ͸ո͍͕͠ɾɾɾ PHP  ⏳estimate: 9~10 /25
53. §3 .1 .2 ⏳estimate: 9~10 /25
54. Α͘ͳͦ͞͏ͳίʔυΛආ͚ΔͨΊʹ  ⏳estimate: 10 /25
55. Τϥʔɺcase-by-case ( ) ( )  ⏳estimate: 10 /25
56. ࣮ྫʂϓϩάϥϛϯά ( ) 
  ⏳estimate: 10~11 /25
57. ࣮ྫʂPHP ( ) 
58. ࣮ྫʂPHP : 
 include E_WARNING require E_ERROR 
 https://www.php.net/manual/ja/function.include.php  ⏳estimate: 10~11 /25
59. ΤϥʔϨϕϧ͸ओ؍తʹܾ·Δ(ଆ໘΋͋Δ)  ⏳estimate: 11 /25
60. ίϨ͸͋ͳͨͷ௚؍ʹ߹͏ʁ E_ERROR 
61. ΤϥʔʹࣖΛ܏͚͍ͯ͜͏ʙ  ⏳estimate: 11 /25
62. ΤϥʔʹࣖΛ܏͚͍ͯ͜͏ʙ 
 
 
  ⏳estimate: 11~12 /25
63. §4 PRO
64. Τϥʔɺා͍Ͱ͔͢ʁ ( )  ⏳estimate: 12 /25
65. ΤϥʔͷPRO͕ɺ஌͍ͬͯΔ͜ͱ 
 
 ( ) 
 
  ⏳estimate: 12~13 /25
66. Τϥʔ͕࣍ͷʮ૝ఆ֎ʯʮᐆດʯΛݺͿ ( )  [ग़య] 
 ᴷAndreas Zeller, தా लج, ࠓా ণ޺, େؠ ঘ޺, ஛ా ߳බ, ٶݪ ٱඒࢠ, फܗ ࣿ৫ 
 σόοάͷཧ࿦ͱ࣮ફ ―ͳͥϓϩάϥϜ͸͏·͘ಈ͔ͳ͍ͷ͔ P3 - P4
67. όά͸ʮൟ৩ʯ͢Δ 1 1  [ग़య] 
 ᴷ Shore, James, Warden, Shane, ฏು ݈ࣇ, ໦Լ ࢙඙, ࡫Ҫ ਸ࢘ 
 ΞʔτɾΦϒɾΞδϟΠϧσϕϩοϓϝϯτ : ૊৫Λ੒ޭʹಋ͘ΤΫετϦʔϜϓϩάϥϛϯά P169
68. Τϥʔ͕ڭ͑ͯ͘ΕΔ͜ͱɾ͘Εͳ͍͜ͱ 
  ⏳estimate: 13~14 /25
69. ͖ͬ͞ͷίʔυ: Կ͕ਖ਼͍͠ʁ  $taxRate 1.8 fl oat 0.8 fl oat 80(%) int ⏳estimate: 13~14 /25
70. ผͷྫ: ߏจΤϥʔ ( ) 7 if{} if {} 🤮  ⏳estimate: 13~14 /25
71. ผͷྫ: ߏจΤϥʔɺ͜ΕͩͬͨΒͲ͏ݟ͑Δʁ class{} 
72. ผͷྫ: ߏจΤϥʔɺݟͨ໨ͰมΘΒͳ͍҆৺ײ  ⏳estimate: 14 /25
73. Τϥʔͱ஥ྑ͘ͳΔʹ͸ PRO  ⏳estimate: 14~15 /25
74. Τϥʔ͸ఢ͡Όͳ͍ɺ༑ୡͳΜͩʂʂ →ͦͷ৺͸ʁ  ⏳estimate: 15~16 /25
75. Τϥʔͱ஥ྑ͘ͳΔͨΊͷίπ΋௫Έ·͠ΐ͏ʂ 
 ( ) = ( )  ⏳estimate: 16 /25
76. §5 PHP
77. §5 PHP .1 .2 ⏳estimate: 16~17 /25
78. ϓϩάϥϛϯάʹͱͬͯΤϥʔ͸ॏཁ  ⏳estimate: 16~17 /25
79. PHP͸Ͳ͏͖ͯͨ͠ʁˠΑ͘࿩୊ʹͳΔ΍ͭ PHP5 -> PHP7 Throwable/Error E_STRICT : E_NOTICE, E_WARNING, E_DEPRECATED PHP7 -> PHP8 warning -> Error PHP8 -> PHP9 Error (8.2 Deprecated) Error 
80. ᐆດ͞ͱͷઓ͍ PHP  ⏳estimate: 17~18 /25
81. ᐆດ͞ͱͷઓ͍ E_WARNING/E_NOTICE Error throw E_NOTICE (7.4 ) E_NOTICE php.ini these are warnings which often result from a bug in your code, but it's possible that it was intentional  ⏳estimate: 17~18 /25
82. php-src grep 7.x NOTICE WARNING 8.x WARNING E_NOTICE/ 
 E_WARNINGͷग़ݱ਺ git --no-pager grep E_NOTICE -- 'ext/**/*.c' | wc -l
83. RFCͳͲ PHP: rfc:engine_warnings 
 https://wiki.php.net/rfc/engine_warnings PHP: rfc:consistent_type_errors 
 https://wiki.php.net/rfc/consistent_type_errors Pull requests · php/php-src 
 https://github.com/php/php-src/pulls?q=label%3A%22Warning+promotion%22 PHP: rfc:unde fi ned_property_error_promotion 
 https://wiki.php.net/rfc/unde fi ned_property_error_promotion PHP: rfc:unde fi ned_variable_error_promotion 
 https://wiki.php.net/rfc/unde fi ned_variable_error_promotion 
84. §5 PHP .1 .2
85. ͜Ε͔ΒͲ͏ͳΓͦ͏ʁ NOTICE 
 PHP Error WARNING (DEPRECATED ) TypeError/ValueError 
86. ͜Ε͔ΒͲ͏͍ͯ͘͠ʁ PHP7.0  ⏳estimate: 20 /25
87. ͜Ε͔ΒͲ͏͍ͯ͘͠ʁ E_NOTICE/E_WARNING (`===` strict ) PHPStan Psalm PHP  ⏳estimate: 21 /25
89. Τϥʔͱ্ख͘෇͖߹͏ͱɺ೉͕͠͞ݮΔ PHP 
  ⏳estimate: 21~22 /25
91. ͓͠·͍ʂ ͓෇͖߹͍͍͖ͨͩ 
 ͋Γ͕ͱ͏͍͟͝·ͨ͠