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_N4").innerHTML = "4";
document.querySelector(".sample01_Q4").innerHTML = "모던, 자바스크립트, 핵심";
document.querySelector(".sample01_M4").innerHTML = "템플릿 문자열";
document.querySelector(".sample01_P4").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;

//결과값 console.log로 확인

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);  //''

const currentStr16 = str1.slice(1, 4);  //ava
const currentStr17 = str1.slice(4, 1);  //''
const currentStr18 = str1.substring(4, 1);  //ava
const currentStr19 = str1.substring(1, 4);  //ava
// substing은 시작위치와 끝나는위치 순서가 바뀌어도 자동으로 바꾸어 출력해줍니다.

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
// * 웹표준에서 사라진 문법

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 currentStr1 = str1.replace("javascript", "자바스크립트");     // 자바스크립트 reference
const currentStr2 = str1.replace("j", "J");     // Javascript reference
const currentStr3 = str1.replace("e", "E");     // javascript rEference
const currentStr4 = str1.replaceAll("e", "E");     // javascript rEfErEncE
const currentStr5 = str1.replace(/e/g, "E");     // javascript rEfErEncE(g : global)
const currentStr6 = str1.replace(/e/gi, "E");     // javascript rEfErEncE(i : 대/소문자)

const str2 = "https://www.naver.com/img01.jpg";  
const currentStr7 = str2.replace("img01.jpg", "img02.jpg");     //img01 -> img02

const str3 = "010-2000-1000";
const currentStr8 = str3.replace("-", "");      //0102000-1000
const currentStr9 = str3.replaceAll("-", "");       //01020001000
const currentStr10 = str3.replace(/-/g, "");       //01020001000
const currentStr11 = str3.replace(/-/g, " ");       //010 2000 1000
const currentStr12 = str3.replace(/-/g, "★");       //010★2000★1000
const currentStr13 = str3.replace(/[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);     //javascriptjavascript

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, "1234");        //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 : 데이터가 없을 때
const currentStr7 = str1.indexOf("b");      //-1 : 데이터가 없을 때
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 : 데이터가 없을 때
const currentStr7 = str1.search("b");      //-1 : 데이터가 없을 때
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']

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 currentStr5 = str1.charCodeAt();    // 106
const currentStr6 = str1.charCodeAt("0"); // 106
const currentStr7 = str1.charCodeAt("1"); // 97
const currentStr8 = 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