Metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 1 akan mengonversi let filename = "index.js"; let extension = filename.split(".").pop(); console.log(extension); // "js" 0 menjadi let filename = "index.js"; let extension = filename.split(".").pop(); console.log(extension); // "js" 1 substring, dipisahkan oleh karakter yang Anda berikan sebagai parameter metode
Berikut adalah contoh metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" _1 dalam tindakan
let filename = "index.js"; let arr = filename.split("."); console.log(arr); // ["index", "js"] _
Selanjutnya, metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" _2 akan menghapus elemen terakhir dari array dan mengembalikannya sebagai nilai. Anda dapat menetapkan hasil pemanggilan metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 2 ke dalam variabel sebagai berikut
let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js"
Sekarang setelah Anda mengetahui cara kerja kedua metode tersebut, Anda dapat memanggil metode tersebut secara berantai untuk mendapatkan ekstensi nama file sebagai berikut
let filename = "index.js"; let extension = filename.split(".").pop(); console.log(extension); // "js" _
Dan begitulah cara Anda mendapatkan ekstensi file dari nama file
Untuk menghindari pengulangan kode setiap kali Anda perlu mengekstrak ekstensi, Anda dapat membuat fungsi kecil bernama let filename = "index.js"; let extension = filename.split(".").pop(); console.log(extension); // "js" 5 yang menerima satu parameter let filename = "index.js"; let extension = filename.split(".").pop(); console.log(extension); // "js" 6 sebagai let filename = "index.js"; let extension = filename.split(".").pop(); console.log(extension); // "js" 0 dan let filename = "index.js"; let extension = filename.split(".").pop(); console.log(extension); // "js" 8 satu-satunya ekstensi sebagai berikut
function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg"
Metode ini juga berfungsi dengan baik saat menerima file dari let filename = "index.js"; let extension = filename.split(".").pop(); console.log(extension); // "js" 9 elemen HTML seperti yang ditunjukkan di bawah ini
<body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body>
Ada satu cara lagi untuk mengekstrak ekstensi file, mari pelajari cara melakukannya selanjutnya
Dapatkan ekstensi nama file menggunakan metode substring() dan lastIndexOf()
Metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 3 adalah metode bawaan dari objek function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" 1 yang mengambil bagian string dari indeks function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" 2 dan function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" 3 yang Anda tentukan sebagai argumennya
Perlu diingat bahwa indeks function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" _3 dikecualikan dari hasil, jadi Anda harus memilih indeks berikutnya dari karakter yang ingin Anda sertakan dalam substring
Misalnya, Anda dapat mengekstrak function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" _5 dari function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" 6 dengan kode berikut
let animal = "Horse"; let extract = animal.substring(1, 4); console.log(extract); // ors
Indeks string dimulai pada function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" 7 sehingga huruf function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" 8 dari function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" 6 akan memiliki indeks <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 0
Huruf <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 1 dari function getExtension(filename) { return filename.split(".").pop(); } let filename = "main.config.js"; let extension = getExtension(filename); console.log(extension); // "js" let photoname = "photo.jpg"; let photoExtension = getExtension(photoname); console.log(photoExtension); // "jpg" 6 memiliki nilai indeks <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 3, jadi Anda harus meletakkan <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 4 sebagai parameter kedua dari metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 3
Saat Anda menghilangkan parameter kedua, metode ini akan mengembalikan sisa string tanpa memotongnya
let animal = "Horse"; let extract = animal.substring(1); console.log(extract); // orse
Berikutnya, let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 4 mengembalikan nilai indeks dari kemunculan terakhir string tertentu. Anda perlu menentukan apa yang ingin Anda cari sebagai argumen untuk metode ini
Misalnya, inilah cara mengembalikan indeks terakhir <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 7 dari <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 8
let fruit = "Banana"; let lastIndex = fruit.lastIndexOf("a"); console.log(lastIndex); // 5
Huruf <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> _7 dari kata <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 8 di atas memiliki nilai indeks <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 0, <body> <h1>Get file extension</h1> <p>Get the extension of a file from user upload</p> <form> <input type="file" id="myFile" /> <button id="checkExt">Check extension</button> </form> <script> let button = document.getElementById("checkExt"); function checkExtension() { let filename = document.querySelector("#myFile").value; let extension = filename.split(".").pop(); document.write(`The file extension is: ${extension}`); } button.addEventListener("click", checkExtension); </script> </body> 3, dan let animal = "Horse"; let extract = animal.substring(1, 4); console.log(extract); // ors 3, jadi metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 4 hanya mengembalikan yang terakhir, yaitu let animal = "Horse"; let extract = animal.substring(1, 4); console.log(extract); // ors 3
Mengetahui cara kerja kedua metode tersebut, Anda dapat memanggil metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 4 untuk mendapatkan posisi indeks dari titik terakhir simbol let animal = "Horse"; let extract = animal.substring(1, 4); console.log(extract); // ors 7 dalam nama file, lalu memanggil metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 3 untuk mengekstrak ekstensi
Ini sebuah contoh
let filename = "presentation.pptx"; let lastIndex = filename.lastIndexOf("."); let extension = filename.substring(lastIndex + 1); console.log(extension); // "pptx"
Agar kode Anda lebih ringkas, Anda dapat memanggil kedua metode dalam satu baris seperti yang ditunjukkan di bawah ini
let filename = "presentation.pptx"; let extension = filename.substring(filename.lastIndexOf(".") + 1); console.log(extension); // "pptx"
Dan begitulah cara Anda mengekstrak ekstensi file menggunakan metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 3 dan let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 4
Sama seperti dengan metode let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 1 dan let arr = ["index", "js"]; let extension = arr.pop(); console.log(arr); // ["index"] console.log(extension); // "js" 2, Anda dapat menulis fungsi pembantu kecil untuk mendapatkan ekstensi sehingga Anda tidak perlu mengulanginya sendiri setiap kali Anda membutuhkannya