删除所有.html文件-如果else语句不起作用

这是我的第一个bash脚本。我需要从当前文件夹中删除所有.html文件。

我有这个：

#!/bin/bash

HTML_FILE_COUNT=$(find . -maxdepth 1 -type f -name "*.html" | wc -l)

echo "Remove $HTML_FILE_COUNT file(s) with .html extension (yes / no)?"

echo -n "Answer: "
read ANSWER

if [ [$ANSWER = "yes"] ]; then
    echo "$(find . -maxdepth 1 -type f -name "*.html" -delete)"
    echo "Files have been removed!"
elif [ [$ANSWER = "no"] ]; then
    echo "No file has been removed!"
else
    echo "Unknown command!" 
fi

但是，该if else块仅返回Unknown command。我在这里想念什么？