includes()

includes()란?

includes()는 문자열 포함 여부를 검색하여, 불린(ture,false)을 반환해주는 메서드 입니다.

const str1 = "sleep cat"
const currentStr1 = str1.includes("sleep"); //true
const currentStr2 = str1.includes("cat"); //true
const currentStr3 = str1.includes("s"); //true
const currentStr4 = str1.includes("b"); //false //포함 여부를 나타냄

"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 //포함 여부를 나타냄
    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