将文本转换为大写、小写、首字母大写或句子大写形式，满足不同场景的文本格式需求
hello world! this is a sample text for case conversion. it demonstrates how this tool works. try it now!
HELLO WORLD! THIS IS A SAMPLE TEXT FOR CASE CONVERSION. IT DEMONSTRATES HOW THIS TOOL WORKS. TRY IT NOW!
hello world! this is a sample text for case conversion. it demonstrates how this tool works. try it now!
Hello World! This Is A Sample Text For Case Conversion. It Demonstrates How This Tool Works. Try It Now!
Hello world! This is a sample text for case conversion. It demonstrates how this tool works. Try it now!