question: public static Boolean isSyntaxValid ( String input ) { if ( input != null ) { Stack < Character > stack = new Stack < Character > ( ) ; if ( input . length ( ) > 0 ) { for ( int i = 0 ; i < input . length ( ) ; i ++ ) { char ch = input . charAt ( i ) ; if ( '\\' == ch ) { i ++ ; continue ; } if ( isValueEnclosingChar ( ch ) ) { if ( EnclosingCharacters . DOUBLE_QUOTATION == ch ) { Character popped = stack . pop ( ) ; if ( popped == EnclosingCharacters . DOUBLE_QUOTATION ) { } else { if ( popped != null ) { stack . push ( popped ) ; } stack . push ( ch ) ; } } else if ( EnclosingCharacters . SINGLE_QUOTATION == ch ) { Character popped = stack . pop ( ) ; if ( popped == EnclosingCharacters . SINGLE_QUOTATION ) { } else { if ( popped != null ) { stack . push ( popped ) ; } stack . push ( ch ) ; } } else { if ( isOpeningBracket ( ch ) ) { stack . push ( ch ) ; } else { Character popped = stack . pop ( ) ; if ( matches ( popped , ch ) ) { } else { return false ; } } } } } } if ( stack . isEmpty ( ) ) { return true ; } else { return false ; } } else { return false ; } }
target:  This function will check for the validity of the input provided. For e.g; '" input"' is valid but '" input' is not a valid input same is the case with input like a JSON string