js转换特殊字符

function htmlEntities(str) {
    return str.replace(/[\u00A0-\u9999<>&](?!#)/gim, function(i) {
        return '&#' + i.charCodeAt(0) + ';';
    });
}

console.log(htmlEntities('<div>你好, World!</div>')); // &lt;div&gt;你好, World!&lt;/div&gt;

function htmlEntitiesDecode(str) {
    var textarea = document.createElement('textarea');
    textarea.innerHTML = str;
    return textarea.value;
}

console.log(htmlEntitiesDecode('&lt;div&gt;你好, World!&lt;/div&gt;')); // <div>你好, World!</div>

function toUnicode(str) {
    return Array.from(str).map(function(char) {
        return '\\u' + char.charCodeAt(0).toString(16).padStart(4, '0');
    }).join('');
}

console.log(toUnicode('你好')); // "\u4f60\u597d"

function fromUnicode(str) {
    return str.replace(/\\u[\dA-Fa-f]{4}/g, function(match) {
        return String.fromCharCode(parseInt(match.replace(/\\u/, ''), 16));
    });
}

console.log(fromUnicode("\u4f60\u597d")); // "你好"