記述演習
ダイアログボクックスに表示
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>あいさつを表示するスクリプト</title> <script> alert('Hello World!!'); </script> </head> <body> </body> </html>
コンソールに表示
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>あいさつを表示するスクリプト</title> <script> console.log('Hello World!!'); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var a = 10; console.log(a); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var a; a = 10; console.log(a); a = 20; console.log(a); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var x = 123 + 456; var y = '123' + '456'; console.log(x); console.log(y); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var a = 10; a = a + 5; console.log(a); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var a = 10; a += 5; console.log(a); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var a = 10; a = a + 1; console.log(a); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var a = 10; a += 1; console.log(a); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var a = 10; a++; console.log(a); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var number = [ 10, 20, 30 ]; console.log(number); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var number = [ 10, 20, 30 ]; console.log(number[1]); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var number = [ 10, 20, 30 ]; number[1] = 50; console.log(number[1]); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var number = [ 10, 20, 30 ]; number[3] = 99; </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var number = [ 10, 20, 30 ]; number[9] = 99; </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var number = []; number[0] = 10; number[1] = 20; number[2] = 30; </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var number = [ 10, 20, 30 ]; console.log(number.length); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var number = [ [ 10 , 20 , 30 ] , [ 40 , 50 , 60 ] ]; console.log(number[0][0]); console.log(number[0][1]); console.log(number[0][2]); console.log(number[1][0]); console.log(number[1][1]); console.log(number[1][2]); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var favorites = { food : 'カレー', color : '青', number : 7 }; </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var favorites = { '食べ物' : 'カレー', '色' : '青', '数字' : 7 }; </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var favorites = { food : 'カレー', color : '青', number : 7 }; console.log(favorites.food); console.log(favorites.color); console.log(favorites.number); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var favorites = { food : 'カレー', color : '青', number : 7 }; console.log(favorites["food"]); var key = 'food'; console.log(favorites[key]); </script> </head> <body> </body> </html>
<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>JavaScriptの練習</title> <script> var favorites = { food : 'カレー', color : '青', number : 7 }; favorites.sports = 'サッカー'; console.log(favorites.sports); </script> </head> <body> </body> </html>
