💾str.slice2()

JS ⟩ primitives ⟩ String ⟩ methods ⟩ .slice2()

returns new substring (Unicode supported)

💾 程式

💾 replit：str.slice2()

// 🔸 str.slice2()
// ⭐ supports surrogate pairs
String.prototype.slice2 = function(start, end) {
  return Array.from(this)    // ⭐ Array.from(string) works fine with unicode.
      .slice(start, end)
      .join('');
};

💈範例：

let str = '𝒳😂𩷶';

str.slice2(1, 3),          // ✅ '😂𩷶'

// ⛔ native methods doesn't support surrogate pairs❗
str.slice(1, 3),           // ❌ �� (garbage)
str.substring(1, 3),       // ❌ �� (garbage)

📗 參考

• JS.info ⟩ iterables

• MasteringJS ⟩ JavaScript substring() vs slice()

📘 手冊

• String.prototype.slice() - returns new (sub)string.

• String.prototype.substring() - returns new (sub)string.

• String.prototype.substr() - depreacate.

👥 相關

• iterator for String works correctly with surrogate pairs.

• str.splice()

• str.words() - of words in a sentence.

🗣 討論

• What is the difference between String.slice and String.substring?