find(), findIndex()

find()

배열 요소 검색 : 반환(요소)

{
    //기본값 : [100, 200, 300, 400, 500]

    const result = arrNum.find(el => el === 300)
    //결과값 : 300

    //기본값 : [100, 200, 300, 400, 500]
    const result2 = arrNum.find(el => el === 600)
    //결과값 : undefined
    
    const arrText3 = ["javascript", "react", "vue"];
    const result3 = arrText3.find(el => el ==="javascript");
    //결과값 : javascript
}

findIndex()

배열 첫 요소 검색 : 반환(숫자)

{
    //기본값 : ['javascript', 'react', 'vue']

    const arrText4 = ["javascript", "react", "vue"];
    const result4 = arrText4.findIndex(el => el ==="javascript");
    //결과값 : 0
    
    const arrTaxt5 = ["javascript", "react", "vue"]
    const result5 = arrTaxt5.findIndex(el => el === "html");    
    //결과값 : -1
}