> For the complete documentation index, see [llms.txt](https://wwydev.gitbook.io/mkdc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wwydev.gitbook.io/mkdc/zhi-nan/tiao-jian-pan-duan.md).

# Condition

Can use the "if" command for conditional judgment.

### define conditional variables

Define conditional variables in the JSON file, which should be of type bool.

{% code title="main.json" %}

```json
{
    "variable1": "hello",
    "variable2": "world",
    "is_show": true,
    "is_show2": false
}
```

{% endcode %}

### use conditional judgment

To use conditional judgment in a markdown file, it needs to start with the "if -" or "if n -" directive and start with "<--- {end}--->"End.

Note: The "ifn -" instruction will logically invert the corresponding variable.

{% code title="main.md" %}

```markdown
<!--{if-is_show}-->
# variable
<!--{v-variable1}--><!--{ifn-is_show2}--> : <!--{v-variable2}--><!--{end}-->
<!--{end}-->
```

{% endcode %}

### compiler results

{% code title="dist/build.md" %}

```markdown
# variable
hello : world
```

{% endcode %}