includes()

12. 문자열 메서드 : 검색 : includes() : 문자열 포함 여부 검색

문자열 포함 여부를 검색하여, 불린(true, false)을 반환합니다.

"문자열".includes(검색값)
"문자열".includes(검색값, 시작값)

const str1 = "javascript reference";
        
const currentStr1 = str1.includes('javascript');            //true
const currentStr2 = str1.includes('j');                     //true
const currentStr3 = str1.includes('b');                     //false
const currentStr4 = str1.includes('reference');                     //true
const currentStr5 = str1.includes('reference', 1);                     //true
const currentStr6 = str1.includes('reference', 11);                     //true
const currentStr7 = str1.includes('reference', 12);                     //false