AWS lambda字符串插值不工作

所以我试图超越lambda环境,我使用了字符串插值,但是有一件事我无法理解,所以下面基本上是我的lambda,如果你看到函数名,它有一个环境的占位符。但是当我像这样部署的时候

aws cloudformation deploy --template-file build/output.yaml --stack-name test-stack --capabilities CAPABILITY_IAM --parameter-overrides Environment=de
v

占位符不更新以下代码

Parameters:
  Environment:
    Type: String

Resources:
    HelloWorldFunction:
        Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
        Properties:
            CodeUri: src
            Handler: index.lambda_handler
            Runtime: python3.6
            FunctionName: HelloLambda-${Environment}
            MemorySize: 128
            Timeout: 30
            Policies:
              - AWSLambdaBasicExecutionRole 

但如果我也这样做的话 参数: 环境: 类型:字符串

资源:

 HelloWorldFunction:
        Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
        Properties:
            CodeUri: src
            Handler: index.lambda_handler
            Runtime: python3.6
            FunctionName: !Sub HelloLambda-${Environment}
            MemorySize: 128
            Timeout: 30
            Policies:
              - AWSLambdaBasicExecutionRole

上面的执行工作,有什么区别吗 FunctionName: !Sub HelloLambda-${Environment} 和 FunctionName: HelloLambda-${Environment}