javascript

{
    const arrNum = [100, 200, 300, 400, 500];
    const arrPush = arrNum.push(600);

    console.log(arrNum)   //[100, 200, 300, 400, 500, 600]


    const arrNum1 = [100, 200, 300, 400, 500];
    const arrPush1 = arrNum1.pop();

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

{
    const arrNum = [100, 200, 300, 400, 500];
    const arrPush = arrNum.unshift(600);

    console.log(arrNum)   //[600, 100, 200, 300, 400, 500]


    const arrNum1 = [100, 200, 300, 400, 500];
    const arrPush1 = arrNum1.shift();

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

{
    ['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']

    console.log(['j','a','v','a','s','c','r','i','p','t'].slice(0));
}

{
const arrNum = [100, 200, 300, 400, 500];
const text1 = arrNum.join('');  //100200300400500
const text2 = arrNum.join(' ');  //100 200 300 400 500
const text3 = arrNum.join('*');  //100*200*300*400*500
const text4 = arrNum.join('-');  //100-200-300-400-500
const text5 = arrNum.join('🍧');  //100-200-300-400-500

console.log(text4)
}

{
    const arrNum1 = [100, 200, 300, 400, 500];
        const result1 = arrNum.splice(1);  

        console.log(result1);   //[200, 300, 400, 500]          //지워진값 출력
        console.log(arrNum1);   //[100]                         //지워진값의 나머지 출력

        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 = arrNum2.splice(1, 4);

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

        const arrNum4 = [100, 200, 300, 400, 500];
        const result4 = arrNum2.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 = arrNum2.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 = arrNum2.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 = arrNum2.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 = arrNum2.splice(-2, 2, "javascript");

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

}