Javascript

//01
const str1 = "자바스크립트";
const str2 = "제이쿼리";

document.querySelector(".sample01_N1").innerHTML = "1";
document.querySelector(".sample01_Q1").innerHTML = "자바스크립트, 제이쿼리";
document.querySelector(".sample01_M1").innerHTML = "문자열(string) 결합";
document.querySelector(".sample01_P1").innerHTML = str1 + str2;

//02
const num1 = 100;
const num2 = 200;

document.querySelector(".sample01_N2").innerHTML = "2";
document.querySelector(".sample01_Q2").innerHTML = "100, 200";
document.querySelector(".sample01_M2").innerHTML = "숫자(number) 결합";
document.querySelector(".sample01_P2").innerHTML = num1 + num2;

//03
const text1 = "모던";
const text2 = "자바스크립트";
const text3 = "핵심";

document.querySelector(".sample01_N3").innerHTML = "3";
document.querySelector(".sample01_Q3").innerHTML = "모던, 자바스크립트, 핵심";
document.querySelector(".sample01_M3").innerHTML = "문자열(string) 결합";
document.querySelector(".sample01_P3").innerHTML = "나는 " + text1 + "(modern) " + text2 + "(javascript) " + text3 + "을 배우고 싶다.";

//04
document.querySelector(".sample01_N3").innerHTML = "4";
document.querySelector(".sample01_Q3").innerHTML = "모던, 자바스크립트, 핵심";
document.querySelector(".sample01_M3").innerHTML = "템플릿 문자열";
document.querySelector(".sample01_P3").innerHTML = `나는 ${text1}(modern) ${text2}(javascript) ${text3}을 배우고 싶다.`;

const str1 = "javascript";
const currentStr1 = str1.toUpperCase();

document.querySelector(".sample02_N1").innerHTML = "1";
document.querySelector(".sample02_Q1").innerHTML = "javascript";
document.querySelector(".sample02_M1").innerHTML = "toUpperCase()";
document.querySelector(".sample02_P1").innerHTML = currentStr1;

const str2 = "JAVASCRIPT";
const currentStr2 = str2.toLowerCase();

document.querySelector(".sample02_N2").innerHTML = "2";
document.querySelector(".sample02_Q2").innerHTML = "JAVASCRIPT";
document.querySelector(".sample02_M2").innerHTML = "toLowerCase()";
document.querySelector(".sample02_P2").innerHTML = currentStr2;

const str1 = "     javascript     ";
const currentStr1 = str1.trim();

document.querySelector(".sample03_N1").innerHTML = "1";
document.querySelector(".sample03_Q1").innerHTML = str1;
document.querySelector(".sample03_M1").innerHTML = "trim()";
document.querySelector(".sample03_P1").innerHTML = currentStr1;

const str2 = "     javascript     ";
const currentStr2 = str2.trimStart();

document.querySelector(".sample03_N2").innerHTML = "2";
document.querySelector(".sample03_Q2").innerHTML = str2;
document.querySelector(".sample03_M2").innerHTML = "trimStart()";
document.querySelector(".sample03_P2").innerHTML = currentStr2;

const str3 = "     javascript     ";
const currentStr3 = str3.trimEnd();

document.querySelector(".sample03_N3").innerHTML = "3";
document.querySelector(".sample03_Q3").innerHTML = str3;
document.querySelector(".sample03_M3").innerHTML = "trimEnd()";
document.querySelector(".sample03_P3").innerHTML = currentStr3;

const str1 = "javascript reference";
const currentStr1 = str1.slice(0);  //javascript reference
const currentStr2 = str1.slice(1);  //avascript reference
const currentStr3 = str1.slice(2);  //vascript reference
const currentStr4 = str1.slice(0, 1);  //j
const currentStr5 = str1.slice(0, 2);  //ja
const currentStr6 = str1.slice(0, 3);  //jav
const currentStr7 = str1.slice(1, 2);  //a
const currentStr8 = str1.slice(1, 3);  //av
const currentStr9 = str1.slice(1, 4);  //avs
const currentStr10 = str1.slice(-1);  //e
const currentStr11 = str1.slice(-2);  //ce
const currentStr12 = str1.slice(-3);  //nce
const currentStr13 = str1.slice(-3, -1);  //nc
const currentStr14 = str1.slice(-3, -2);  //n
const currentStr15 = str1.slice(-3, -3);  //''(마이너스도 어디가 더 큰지)

const currentStr16 = str1.slice(1, 4);  //ava
const currentStr17 = str1.slice(4, 1);  //''
const currentStr18 = str1.substring(1, 4);  //ava
const currentStr19 = str1.substring(4, 1);  //ava  (순서를 다르게 해도 자동으로 출력)

const currentStr20 = str1.substr(0);  //javascript reference
const currentStr21 = str1.substr(1);  //avascript reference
const currentStr22 = str1.substr(2);  //vascript reference
const currentStr23 = str1.substr(0, 1);  //j
const currentStr24 = str1.substr(0, 2);  //ja
const currentStr25 = str1.substr(0, 3);  //jav
const currentStr26 = str1.substr(1, 2);  //av
const currentStr27 = str1.substr(1, 3);  //ava
const currentStr28 = str1.substr(1, 4);  //avas
const currentStr29 = str1.substr(-1);  //e
const currentStr30 = str1.substr(-2);  //ce
const currentStr31 = str1.substr(-3);  //nce
const currentStr32 = str1.substr(-1, 1);  //e
const currentStr33 = str1.substr(-2, 2);  //ce
const currentStr34 = str1.substr(-3, 3);  //nce

const str1 = "javascript reference";
const currentStr1 = str1.split('');      // ['j','a','v','a','s','c','r','i','p','t','','r','e','f','e','r','e','n','c','e']
const currentStr2 = str1.split(' ');     // ['javascript', 'reference']
const currentStr3 = str1.split('', 1);   // ['j']
const currentStr4 = str1.split('', 2);   // ['j', 'a']
const currentStr5 = str1.split(' ', 1);  // ['javascript']
const currentStr6 = str1.split(' ', 2);  // ['javascript', 'reference']
const currentStr7 = str1.split('j');     // ['', 'avascript reference']
const currentStr8 = str1.split('a');     // ['j', 'v', 'script reference']
const currentStr9 = str1.split('e');     // ['javascript r', 'f', 'r', 'nc', '']

const str2 = "java/script/refer/ence";
const currentStr10 = str2.split('/');    // ['java', 'script', 'refer', 'ence']

const str3 = "java&script&refer!ence";
const currentStr11 = str3.split('!');       // ['java&script&refer', 'ence']
const currentStr12 = str3.split('&');       // ['java', 'script', 'refer!ence']
const currentStr13 = str3.split(/&|\!/);    // ['java', 'script', 'refer', 'ence']

const str4 = "javascript reference";
const currentStr14 = str4.split('').join();                 //j,a,v,a,s,c,r,i,p,t, ,r,e,f,e,r,e,n,c,e
const currentStr15 = str4.split('').join('*');              //j*a*v*a*s*c*r*i*p*t* *r*e*f*e*r*e*n*c*e
const currentStr16 = str4.split('').reverse().join();       //e,c,n,e,r,e,f,e,r, ,t,p,i,r,c,s,a,v,a,j
const currentStr17 = str4.split('').reverse().join('/');    //e/c/n/e/r/e/f/e/r/ /t/p/i/r/c/s/a/v/a/j

const str1 = "javascript reference";
const cirrentStr1 = str1.replace("javascript", "자바스크립트");     //자바스크립트 reference
const cirrentStr2 = str1.replace("j", "J");                     //Javascript reference
const cirrentStr3 = str1.replace("e", "E");                     //javascript rEference
const cirrentStr4 = str1.replaceAll("e", "E");                  //javascript rEfErEncE
const cirrentStr5 = str1.replace(/e/g, "E");                    //javascript rEfErEncE
const cirrentStr6 = str1.replace(/e/gi, "E");                   //javascript rEfErEncE

const str2 = "https://www.naver.com/img01.jpg";
const cirrentStr7 = str2.replace("img01.jpg", "img02.jpg");  

const str3 = "010-2000-1000";
const cirrentStr8 = str3.replace("-", "");              //0102000-1000
const cirrentStr9 = str3.replaceAll("-", "");           //01020001000
const cirrentStr10 = str3.replaceAll(/-/g, "");         //01020001000
const cirrentStr11 = str3.replaceAll(/-/g, " ");        //010 2000 1000
const cirrentStr12 = str3.replaceAll(/[1-9]/g, "*");    //0*0-*000-*000

const str1 = "javascript";
const currentStr1 = str1.concat("reference");                           //javascriptreference
const currentStr2 = str1.concat(" ", "reference");                      //javascript reference
const currentStr3 = str1.concat(", ", "reference");                     //javascript, reference
const currentStr4 = str1.concat(", ", "reference", ", ", "book");       //javascript, reference, book
const currentStr5 = str1.concat(",", ["reference","book"]);             //javascript,reference,book

const str1 = "javascript";
const currentStr1 = str1.repeat(0);     //''
const currentStr2 = str1.repeat(1);     //javascript
const currentStr3 = str1.repeat(2);     //javascript javascript

const str1 = "456";
const currentStr1 = str1.padStart(1, "0");          //456
const currentStr2 = str1.padStart(2, "0");          //456
const currentStr3 = str1.padStart(3, "0");          //456
const currentStr4 = str1.padStart(4, "0");          //0456
const currentStr5 = str1.padStart(5, "0");          //00456
const currentStr6 = str1.padStart(6, "0");          //000456
const currentStr7 = str1.padStart(6, "1");          //111456
const currentStr8 = str1.padStart(6, "12");         //121456
const currentStr9 = str1.padStart(6, "123");        //123456
const currentStr10 = str1.padStart(6, "1234");      //123456
const currentStr11 = str1.padStart(6);              //   456

const currentStr12 = str1.padEnd(1, "0");           //456
const currentStr13 = str1.padEnd(2, "0");           //456
const currentStr14 = str1.padEnd(3, "0");           //456
const currentStr15 = str1.padEnd(4, "0");           //4560
const currentStr16 = str1.padEnd(5, "0");           //45600
const currentStr17 = str1.padEnd(6, "0");           //456000
const currentStr18 = str1.padEnd(6, "1");           //456111
const currentStr19 = str1.padEnd(6, "12");          //456121
const currentStr20 = str1.padEnd(6, "123");         //456123
const currentStr21 = str1.padEnd(6, "124");         //456123
const currentStr22 = str1.padEnd(6);                //456___

const str1 = "javascript reference";
const currentStr1 = str1.indexOf("javascript");        //0
const currentStr2 = str1.indexOf("reference");         //11
const currentStr3 = str1.indexOf("j");                 //0
const currentStr4 = str1.indexOf("a");                 //1
const currentStr5 = str1.indexOf("v");                 //2
const currentStr6 = str1.indexOf("jquery");            //-1
const currentStr7 = str1.indexOf("b");                 //-1
const currentStr8 = str1.indexOf("javascript", 0);     //0
const currentStr9 = str1.indexOf("javascript", 1);     //-1
const currentStr10 = str1.indexOf("reference", 0);     //11
const currentStr11 = str1.indexOf("reference", 1);     //11
const currentStr12 = str1.indexOf("reference", 11);    //11
const currentStr13 = str1.indexOf("reference", 12);    //-1

const currentStr14 = str1.lastIndexOf("javascript");        //0
const currentStr15 = str1.lastIndexOf("reference");         //11
const currentStr16 = str1.lastIndexOf("j");                 //0
const currentStr17 = str1.lastIndexOf("a");                 //3
const currentStr18 = str1.lastIndexOf("v");                 //2
const currentStr19 = str1.lastIndexOf("jquery");            //-1
const currentStr20 = str1.lastIndexOf("b");                 //-1
const currentStr21 = str1.lastIndexOf("javascript", 0);     //0
const currentStr22 = str1.lastIndexOf("javascript", 1);     //0
const currentStr23 = str1.lastIndexOf("reference", 0);      //-1
const currentStr24 = str1.lastIndexOf("reference", 1);      //-1
const currentStr25 = str1.lastIndexOf("reference", 11);     //11
const currentStr26 = str1.lastIndexOf("reference", 12);     //11

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

const str1 = "javascript reference";
const currentStr1 = str1.search("javascript");         //0
const currentStr2 = str1.search("reference");          //11
const currentStr3 = str1.search("j");                  //0
const currentStr4 = str1.search("a");                  //1
const currentStr5 = str1.search("v");                  //2
const currentStr6 = str1.search("jquery");             //-1
const currentStr7 = str1.search("b");                  //-1
const currentStr8 = str1.search(/[a-z]/g);             //0

const str1 = "javascript reference";
const currentStr1 = str1.match("javascript");       //javascript
const currentStr2 = str1.match("reference");        //reference
const currentStr3 = str1.match("r");                //r
const currentStr4 = str1.match(/reference/);        //reference
const currentStr5 = str1.match(/Reference/);        //null
const currentStr6 = str1.match(/Reference/i);       //reference
const currentStr7 = str1.match(/r/g);               //['r', 'r', 'r']
const currentStr8 = str1.match(/e/g);               //['e', 'e', 'e', 'e']

//"문자열".charAt(숫자);

const str1 = "javascript reference";
const currentStr1 = str1.charAt();      //j
const currentStr2 = str1.charAt("0");   //j
const currentStr3 = str1.charAt("1");   //a
const currentStr4 = str1.charAt("2");   //v

const cirrentStr5 = str1.charCodeAt();      //106
const cirrentStr6 = str1.charCodeAt("0");   //106
const cirrentStr7 = str1.charCodeAt("1");   //97
const cirrentStr8 = str1.charCodeAt("2");   //118

const str1 = "javascript reference";
const currentStr1 = str1.startsWith('javascript');      //true
const currentStr2 = str1.startsWith('j');               //true
const currentStr3 = str1.startsWith('java');            //true
const currentStr4 = str1.startsWith('reference');       //false
const currentStr5 = str1.startsWith();                  //false
const currentStr6 = str1.startsWith('');                //true
const currentStr7 = str1.startsWith('reference', 7);    //false
const currentStr8 = str1.startsWith('reference', 11);   //true

const currentStr9 = str1.endsWith('reference');         //true
const currentStr10 = str1.endsWith('e');                //true
const currentStr11 = str1.endsWith('refer');            //false
const currentStr12 = str1.endsWith('javascript');       //false
const currentStr13 = str1.endsWith();                   //false
const currentStr14 = str1.endsWith('');                 //true
const currentStr15 = str1.endsWith('reference', 7);     //false
const currentStr16 = str1.endsWith('reference', 20);    //true