배열 메서드 : slice()

"문자열".slice(시작위치,[종료위치])
  • slice() 메서드는 시작 위치에서 종료 위치 값을 추출하여, 새로운 배열을 반환합니다
{
    ['j','a','v','s','c','r','i','p','t'].slice(0)
    ['j','a','v','a','s','c','r','i','p','t'].slice(0) //['j', 'a', 'v', 'a', 's', 'c', 'r', 'i', 'p', 't']
    ['j','a','v','a','s','c','r','i','p','t'].slice(1) //['a', 'v', 'a', 's', 'c', 'r', 'i', 'p', 't']
    ['j','a','v','a','s','c','r','i','p','t'].slice(2)//['v', 'a', 's', 'c', 'r', 'i', 'p', 't']
    ['j','a','v','a','s','c','r','i','p','t'].slice(0,1)//['j']
    ['j','a','v','a','s','c','r','i','p','t'].slice(1,2)//['a']
    ['j','a','v','a','s','c','r','i','p','t'].slice(0,2)//['j','a']
    ['j','a','v','a','s','c','r','i','p','t'].slice(0,3)//['j','a','v']
    ['j','a','v','a','s','c','r','i','p','t'].slice(5,10)//['c','r','i','p','t']
    ['j','a','v','a','s','c','r','i','p','t'].slice(5,-1)//['c','r','i','p']
    ['j','a','v','a','s','c','r','i','p','t'].slice(5,-2)//['c','r','i']
    ['j','a','v','a','s','c','r','i','p','t'].slice(-1)//['t']
    ['j','a','v','a','s','c','r','i','p','t'].slice(-2)//['p','t']
    ['j','a','v','a','s','c','r','i','p','t'].slice(-3)//['i','p','t']
    ['j','a','v','a','s','c','r','i','p','t'].slice(-3,-1)//['i','p']
    ['j','a','v','a','s','c','r','i','p','t'].slice(-3,-2)//['i']    
}

배열 메서드 : splice()

"문자열".splice(시작위치,[삭제할 갯수],[추가할 요소])
  • splice() 메서드는 배열의 기존 요소를 삭제 또는 교체하거나 새 요소를 추가하여 배열의 내용을 변환합니다.
{
    const arrNum1 = [100,200,300,400,500];
    const result1 = arrNum1.splice(1);

    // console.log(result1)     //[200, 300, 400, 500]
    // console.log(arrNum1)     //[100]

    const arrNum2 = [100,200,300,400,500];
    const result2 = arrNum2.splice(1,2);

    // console.log(result2)        //[200, 300]
    // console.log(arrNum2)        //[100, 400, 500]

    const arrNum3 = [100,200,300,400,500];
    const result3 = arrNum3.splice(1,4);

    // console.log(result3)        //[200, 300, 400, 500]
    // console.log(arrNum3)        //[100]

    const arrNum4 = [100,200,300,400,500];
    const result4 = arrNum4.splice(1,2, "javascript");

    // console.log(result4)        //[200, 300]
    // console.log(arrNum4)        //[100, "javascript", 400, 500]

    const arrNum5 = [100,200,300,400,500];
    const result5 = arrNum5.splice(1,0, "javascript");

    // console.log(result5)        //[]
    // console.log(arrNum5)        //[100, "javascript", 200, 300, 400, 500]

    const arrNum6 = [100,200,300,400,500];
    const result6 = arrNum6.splice(0,4, "javascript");

    // console.log(result6)        //[100,200,300,400]
    // console.log(arrNum6)        //["javascript",500]

    const arrNum7 = [100,200,300,400,500];
    const result7 = arrNum7.splice(2,2, "javascript","react");

    // console.log(result7)        //[300, 400]
    // console.log(arrNum7)        //[100, 200, 'javascript', 'react', 500]

    const arrNum8 = [100,200,300,400,500];
    const result8 = arrNum8.splice(-2,2, "javascript");

    console.log(result8)        //[400, 500]
    console.log(arrNum8)        //[100, 200, 300, 'javascript']
}