[JavaScript] 숫자를 서수(Ordinal Number)로 변환하기 (convert numbers to ordinal numbers)

 

서수 변환 규칙

• 1로 끝나는 숫자는 st를 붙임
• 2로 끝나는 숫자는 nd를 붙임
• 3으로 끝나는 숫자는 rd를 붙임
• 뒤에 'teen'이 붙는 11, 12, 13은 th를 붙임
• 나머지 모든 숫자는 th를 붙임

 

// 숫자를 넘겨받아 서수형 문자열 반환
function convertOrdinalNumber(n)
{
    n = parseInt(n, 10);
    const suffix = ['th', 'st', 'nd', 'rd'];
    const mod100 = n % 100;
 
    return n+(suffix[(mod100-20)%10] || suffix[mod100] || suffix[0]);
}
 
 
 
 
// 테스트
for (let i=0; i<120; i++) {
    console.log(`${i} = ${convertOrdinalNumber(i)}`);
}
 
 
// 결과
0 = 0th
1 = 1st
2 = 2nd
3 = 3rd
4 = 4th
5 = 5th
6 = 6th
7 = 7th
8 = 8th
9 = 9th
10 = 10th
11 = 11th
12 = 12th
13 = 13th
14 = 14th
15 = 15th
16 = 16th
17 = 17th
18 = 18th
19 = 19th
20 = 20th
21 = 21st
22 = 22nd
23 = 23rd
24 = 24th
25 = 25th
26 = 26th
27 = 27th
28 = 28th
29 = 29th
30 = 30th
31 = 31st
32 = 32nd
33 = 33rd
34 = 34th
35 = 35th
36 = 36th
37 = 37th
38 = 38th
39 = 39th
40 = 40th
41 = 41st
42 = 42nd
43 = 43rd
44 = 44th
45 = 45th
46 = 46th
47 = 47th
48 = 48th
49 = 49th
50 = 50th
51 = 51st
52 = 52nd
53 = 53rd
54 = 54th
55 = 55th
56 = 56th
57 = 57th
58 = 58th
59 = 59th
60 = 60th
61 = 61st
62 = 62nd
63 = 63rd
64 = 64th
65 = 65th
66 = 66th
67 = 67th
68 = 68th
69 = 69th
70 = 70th
71 = 71st
72 = 72nd
73 = 73rd
74 = 74th
75 = 75th
76 = 76th
77 = 77th
78 = 78th
79 = 79th
80 = 80th
81 = 81st
82 = 82nd
83 = 83rd
84 = 84th
85 = 85th
86 = 86th
87 = 87th
88 = 88th
89 = 89th
90 = 90th
91 = 91st
92 = 92nd
93 = 93rd
94 = 94th
95 = 95th
96 = 96th
97 = 97th
98 = 98th
99 = 99th
100 = 100th
101 = 101st
102 = 102nd
103 = 103rd
104 = 104th
105 = 105th
106 = 106th
107 = 107th
108 = 108th
109 = 109th
110 = 110th
111 = 111th
112 = 112th
113 = 113th
114 = 114th
115 = 115th
116 = 116th
117 = 117th
118 = 118th
119 = 119th