DECLARE @Str VARCHAR(MAX);

-- The Example from the QOTD
SET @Str=REPLICATE('*',10000) + REPLICATE('*',10000);
PRINT LEN(@Str);

-- Explicitly CAST the Replicated character as type VARCHAR(MAX)
SET @Str=REPLICATE(CAST('*' AS VARCHAR(MAX)),10000) + REPLICATE(CAST('*' AS VARCHAR(MAX)),10000);
PRINT LEN(@Str);

-- Explicitly CAST the results from REPLICATE statements as VARCHAR(MAX), without casting the Replicated character as VARCHAR(MAX)
SET @Str=CAST(REPLICATE('*',10000) AS VARCHAR(MAX)) + CAST(REPLICATE('*',10000) AS VARCHAR(MAX));
PRINT LEN(@Str);

8000
20000
16000

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