text: let c = '😀'
  
  console.log(c.charAt(0))
  console.log(c.charCodeAt(0), c.charCodeAt(1))
  
  const uc = c.normalize('NFC')
  console.log(`length: ${c.length} charAt: ${c.charAt(0)} unicode: c.codePoint(0)`)
  //有些东西没有确定
  