javascript - 什么是console.log？(What is console.log?)

Question

What is the use of console.log ?

(console.log什么用？)

Please explain how to use it in JavaScript, with a code example.

(请通过代码示例说明如何在JavaScript中使用它。)

  ask by Mihir translate from so

Answer 1

It's not a jQuery feature but a feature for debugging purposes.

(它不是jQuery功能，而是用于调试的功能。)

You can for instance log something to the console when something happens.

(例如，您可以在发生某些情况时将某些内容记录到控制台。)

For instance:

(例如：)

$('#someButton').click(function() {
  console.log('#someButton was clicked');
  // do something
});

You'd then see #someButton was clicked in Firebug's “Console” tab (or another tool's console — eg Chrome's Web Inspector) when you would click the button.

(然后，您会#someButton was clicked Firebug的“控制台”选项卡（或其他工具的控制台，例如Chrome的Web Inspector）中看到#someButton was clicked了#someButton was clicked 。)

For some reasons, the console object could be unavailable.

(由于某些原因，控制台对象可能不可用。)

Then you could check if it is - this is useful as you don't have to remove your debugging code when you deploy to production:

(然后，您可以检查它是否有用-这很有用，因为在部署到生产环境时不必删除调试代码：)

if (window.console && window.console.log) {
  // console is available
}