string-format: String.format/formatted/printf cheat sheet module (specifier anatomy, rounding vs C printf, locales, Indian lakh/crore grouping Formatter cannot do, format exceptions, %t dates, concat cost), 11 contract tests

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_017ic4b7Sr2zcoRD2watXv1G

string-format/output/07-formatted-printf.txt

@@ -0,0 +1,22 @@
+== four spellings, one result ==
+Hi Asha, 3 items, Rs 1499.50
+Hi Asha, 3 items, Rs 1499.50
+Hi Asha, 3 items, Rs 1499.50
+Hi Asha, 3 items, Rs 1499.50
+format == formatted == Formatter: true
+
+== formatted() on a text block ==
+Invoice for Asha
+  items :     3
+  total :   1,499.50
+
+== printf returns the PrintStream, so calls chain ==
+one two three
+
+== %n vs \n ==
+true on this platform (line.separator is \n)
+
+== an array argument: spread as the varargs, unless you cast it to Object ==
+x-1
+p-q
+true