render('My name is {name}'， {
  name: 'hsfzxjy'
}); // My name is hsfzxjy

render('I am in {profile.location}', {
  name: 'hsfzxjy',
  profile: {
    location: 'Guangzhou'
  }
}); // I am in Guangzhou

render('{ greeting }. \\{ This block will not be rendered }', {
  greeting: 'Hi'
}); // Hi. { This block will not be rendered }

function render(template, context) {

}

var reg = /\{([^\{\}]+)\}/g;

var reg = /(\\)?\{([^\{\}\\]+)(\\)?\}/g;
// 若是第一个或第三个分组值不为空，则不渲染
现在，代码应该是这样：

function render(template, context) {

  var tokenReg = /(\\)?\{([^\{\}\\]+)(\\)?\}/g;

  return template.replace(tokenReg, function (word, slash1, token, slash2) {
    if (slash1 || slash2) { // 匹配到转义字符
      return word.replace('\\', ''); // 如果 分隔符被转义，则不渲染
    }

    // ...
  })
}

var variables = token.replace(/\s/g, '').split('.'); // 切割 token
var currentObject = context;
var i, length, variable;

// 逐级查找 context
for (i = 0, length = variables.length, variable = variables[i]; i < length; ++i)
  currentObject = currentObject[variable];

return currentObject;

var variables = token.replace(/\s/g, '').split('.'); // 切割 token
var currentObject = context;
var i, length, variable;

for (i = 0, length = variables.length, variable = variables[i]; i < length; ++i) {
  currentObject = currentObject[variable];
  if (currentObject === undefined || currentObject === null) return ''; // 如果当前索引的对象不存在，则直接返回空字符串。
}

return currentObject;

function render(template, context) {

  var tokenReg = /(\\)?\{([^\{\}\\]+)(\\)?\}/g;

  return template.replace(tokenReg, function (word, slash1, token, slash2) {
    if (slash1 || slash2) { 
      return word.replace('\\', '');
    }

    var variables = token.replace(/\s/g, '').split('.');
    var currentObject = context;
    var i, length, variable;

    for (i = 0, length = variables.length, variable = variables[i]; i < length; ++i) {
      currentObject = currentObject[variable];
      if (currentObject === undefined || currentObject === null) return '';
    }

    return currentObject;
  })
}

String.prototype.render = function (context) {
  return render(this, context);
};

"{greeting}! My name is { author.name }.".render({
  greeting: "Hi",
  author: {
    name: "hsfzxjy"
  }
});
// Hi! My name is hsfzxjy.