test length length Google 6 length 0 test empty not empty FALSE Google empty TRUE test create text single text Hello Hello double text K 9 K9 triple text 1 2 3 123 test append item item Miserable item Failure append text item MiserableFailure item 12 item 34 append number item 1234 test substring text 123456789 substring # start FROM_START FROM_START text 2 3 23 substring # end FROM_END FROM_END text 3 2 78 substring first-last FIRST LAST text text test find first find FIRST Banana an 2 last find LAST Banana an 4 no find FIRST Banana Peel 0 test letter letter # FROM_START Blockly 3 o letter # from end FROM_END Blockly 3 k first letter FIRST Blockly B last letter LAST Blockly y random letter TRUE POSITIVE FIRST Blockly RANDOM Blockly test case uppercase UPPERCASE Hello World HELLO WORLD lowercase LOWERCASE Hello World hello world titlecase TITLECASE heLLo WorlD Hello World test trim trim both BOTH abc def abc def trim left LEFT abc def abc def trim right RIGHT abc def abc def