console.assert(value[, ...message])


  • value <any> 测试为真的值。
  • ...message <any> 除了 value 之外的所有参数都用作错误消息。

如果 value假值或省略,则 console.assert() 写入一条消息。 它只写入一条消息,不会影响执行。 输出始终以 "Assertion failed" 开头。 如果提供,则使用 util.format() 格式化 message

如果 value真值,则什么也不会发生。

console.assert(true, 'does nothing');

console.assert(false, 'Whoops %s work', 'didn\'t');
// Assertion failed: Whoops didn't work

console.assert();
// Assertion failed
  • value <any> The value tested for being truthy.
  • ...message <any> All arguments besides value are used as error message.

console.assert() writes a message if value is falsy or omitted. It only writes a message and does not otherwise affect execution. The output always starts with "Assertion failed". If provided, message is formatted using util.format().

If value is truthy, nothing happens.

console.assert(true, 'does nothing');

console.assert(false, 'Whoops %s work', 'didn\'t');
// Assertion failed: Whoops didn't work

console.assert();
// Assertion failed