javascript安全字符串，参考Handlebars.js的实现

safeString.js

function safeString(string) {
    if(!string) {
        return "";
    }
    var escape = {
        "&": "&",
        "<": "&lt;",
        ">": "&gt;",
        '"': "&quot;",
        "'": "&#x27;",
        "`": "&#x60;"
    };
    var badChars = /[&<>"'`]/g;
    
    return string.replace(badChars, function(chr) {
        return escape[chr];
    });
}