react-bits：条件渲染

react-bits
原文

条件渲染时可以使用if/else，但当更复杂或需要判断的变量更多时，推荐分离组件替代

//if
function render() {
  return condition && <span>Rendered when `truthy`</span>
}

// unless
function render() {
  return condition || <span>Rendered when `falsey`</span>
}

// if- else (tidy one - liners)
function render() {
  return condition
    ? <span>Rendered when `truthy`</span>
    : <span>Rendered when `falsey`</span>
}

// if- else (big blocks)
function render() {
  return condition ? (
    <span>
      Rendered when `truthy`
    </span>
  ) : (
    <span>
      Rendered when `falsey`
    </span>
  )
}

使用falsy或truthy（非布尔值）合并逻辑运算符

const Oops = ({showFirst,dontShowSecond}) => (
  <div>
    {showFirst && 'first'}
    {dontShowSecond || 'second'}
  </div>
)

使用!!将输入转换成布尔值

const Oops = ({showFirst,dontShowSecond}) => (
  <div>
    {!!showFirst && 'first'}
    {!!dontShowSecond || 'second'}
  </div>
)