[javascript]padStart() / padEnd()

padStart() / padEnd()

padStart()/padEnd() 메서드는 주어진 길이에 맞게 앞/뒤 문자열을 채우고, 새로운 문자열을 반환합니다.

"문자열".padStart(길이)
"문자열".padStart(길이, 문자열)

const str1 = "456";
const currentStr1 = str1.padStart(1, "0"); 
const currentStr2 = str1.padStart(2, "0"); 
const currentStr3 = str1.padStart(3, "0");
const currentStr4 = str1.padStart(4, "0"); 
const currentStr5 = str1.padStart(5, "0"); 
const currentStr6 = str1.padStart(6, "0"); 
const currentStr7 = str1.padStart(6, "1"); 
const currentStr8 = str1.padStart(6, "12");  
const currentStr9 = str1.padStart(6, "123");  
const currentStr10 = str1.padStart(6, "1234");  //자릿수 안 맞아서 '4'가 잘림
const currentStr11 = str1.padStart(6);  //앞에 공백으로 처리

const currentStr12 = str1.padEnd(1, "0"); 
const currentStr13 = str1.padEnd(2, "0"); 
const currentStr14 = str1.padEnd(3, "0"); 
const currentStr15 = str1.padEnd(4, "0");  
const currentStr16 = str1.padEnd(5, "0"); 
const currentStr17 = str1.padEnd(6, "0"); 
const currentStr18 = str1.padEnd(6, "1"); 
const currentStr19 = str1.padEnd(6, "12");  
const currentStr20 = str1.padEnd(6, "123");  
const currentStr21 = str1.padEnd(6, "1234");  
const currentStr22 = str1.padEnd(6);  //뒤에 공백으로 처리

결과보기

456
456
456
0456
00456
000456
111456
121456
123456
123456
456
456
456
456
4560
45600
456000
456111
456121
456123
456123
456