padStart() / padEnd()

11. 문자열 메서드 : 변경 : padStart() / padEnd() : 문자열 추가

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");  //456
const currentStr2 = str1.padStart(2,"0");  //456
const currentStr3 = str1.padStart(3,"0");  //456
const currentStr4 = str1.padStart(4,"0");  //0456
const currentStr5 = str1.padStart(5,"0");  //00456
const currentStr6 = str1.padStart(6,"0");  //000456
const currentStr7 = str1.padStart(6,"1");  //111456
const currentStr8 = str1.padStart(6,"12");  //121456
const currentStr9 = str1.padStart(6,"123");  //123456
const currentStr10 = str1.padStart(6,"1234");  //123456
const currentStr11 = str1.padStart(6,"");  //   456

const currentStr12 = str1.padEnd(1,"0");  //   456
const currentStr13 = str1.padEnd(2,"0");  //   456
const currentStr14 = str1.padEnd(3,"0");  //   4560
const currentStr15 = str1.padEnd(4,"0");  //   4560
const currentStr16 = str1.padEnd(5,"0");  //   45600
const currentStr17 = str1.padEnd(6,"0");  //   456000
const currentStr18 = str1.padEnd(6,"1");  //   456111
const currentStr19 = str1.padEnd(6,"12");  //   456121
const currentStr20 = str1.padEnd(6,"123");  //   456123
const currentStr21 = str1.padEnd(6,"1234");  //   456123
const currentStr22 = str1.padEnd(6);  //   456___