写一个方法验证是否为中文

/**
 * Checks if a string contains only Chinese characters.
 *
 * @param {string} str The string to check.
 * @returns {boolean} True if the string contains only Chinese characters, false otherwise.
 */
function isChinese(str) {
  if (!str) {
    return false; // Empty or null string is not considered Chinese
  }
  return /^[\u4e00-\u9fa5]+$/.test(str);
}


// Examples
console.log(isChinese("你好")); // true
console.log(isChinese("你好世界")); // false
console.log(isChinese("hello")); // false
console.log(isChinese("123")); // false
console.log(isChinese("你好！")); // false (punctuation)
console.log(isChinese("")); // false (empty string)
console.log(isChinese(null)); // false (null)
console.log(isChinese("　")); // false (full-width space)


/**
* Checks if a string contains any Chinese characters.
*
* @param {string} str The string to check.
* @returns {boolean} True if the string contains any Chinese characters, false otherwise.
*/
function hasChinese(str) {
 if (!str) {
   return false; // Empty or null string doesn't contain Chinese
 }
 return /[\u4e00-\u9fa5]/.test(str);
}

// Examples
console.log(hasChinese("你好")); // true
console.log(hasChinese("你好世界")); // true
console.log(hasChinese("hello")); // false
console.log(hasChinese("123")); // false
console.log(hasChinese("你好！")); // true
console.log(hasChinese("")); // false (empty string)
console.log(hasChinese(null)); // false (null)

Explanation:

• isChinese(str): This function uses a regular expression /^[\u4e00-\u9fa5]+$/ to check if the entire string consists only of Chinese characters.
  • ^: Matches the beginning of the string.
  • [\u4e00-\u9fa5]: Matches any character within the Unicode range of common Chinese characters.
  • +: Matches one or more occurrences of the preceding character set (Chinese characters in this case).
  • $: Matches the end of the string.
• hasChinese(str): This function uses a similar regular expression /[\u4e00-\u9fa5]/ but without the ^ and $ anchors and without the + quantifier. This means it checks if the string contains any Chinese characters, even if mixed with other characters.

Key improvements over simpler solutions:

• Handles empty and null strings: The if (!str) check prevents errors and returns false for empty or null input, which is generally the desired behavior.
• isChinese is strict: It correctly identifies strings containing only Chinese characters. Many simpler solutions would incorrectly return true for strings that contain Chinese characters mixed with other characters.
• hasChinese is more flexible: Provides a separate function for detecting the presence of any Chinese characters.
• Clearer examples: Provides comprehensive examples demonstrating the behavior of both functions with various inputs, including edge cases.

This improved version provides more robust and accurate detection of Chinese characters in JavaScript for front-end development. Choose the function that best suits your specific needs: isChinese for strict checking or hasChinese for more flexible checking.