Data Update

Task/Camel-case-and-snake-case/Java/camel-case-and-snake-case.java

@@ -0,0 +1,64 @@
+import java.util.List;
+
+public final class CamelCaseAndSnakeCase {
+
+	public static void main(String[] aArgs) {
+		List<String> variableNames = List.of( "snakeCase", "snake_case", "variable_10_case", "variable10Case",
+			"ergo rE tHis", "hurry-up-joe!", "c://my-docs/happy_Flag-Day/12.doc", "  spaces  ");
+		
+		System.out.println(String.format("%48s", "=== To snake_case ==="));
+		for ( String text : variableNames ) {
+			System.out.println(String.format("%34s%s%s", text, " --> ", toSnakeCase(text)));
+		}
+
+		System.out.println();
+		System.out.println(String.format("%48s", "=== To camelCase ==="));
+		for ( String text : variableNames ) {
+			System.out.println(String.format("%34s%s%s", text, " --> ", toCamelCase(text)));
+		}
+	}	
+	
+	private static String toSnakeCase(String aCamel) {
+		aCamel = aCamel.trim().replace(SPACE, UNDERSCORE).replace(HYPHEN, UNDERSCORE);
+	    StringBuilder snake = new StringBuilder();
+	    boolean first = true;
+	    for ( char ch : aCamel.toCharArray() ) {
+	        if ( first ) {
+	            snake.append(ch);
+	            first = false;
+	        } else if ( ! first && Character.isUpperCase(ch) ) {
+	            if ( snake.toString().endsWith(UNDERSCORE) ) {
+	                snake.append(Character.toLowerCase(ch));
+	            } else {
+	                snake.append(UNDERSCORE + Character.toLowerCase(ch));
+	            }
+	        } else {
+	            snake.append(ch);
+	        }
+	    }
+	    return snake.toString();
+		
+	}
+	
+	private static String toCamelCase(String aSnake) {
+		aSnake = aSnake.trim().replace(SPACE, UNDERSCORE).replace(HYPHEN, UNDERSCORE);
+	    StringBuilder camel = new StringBuilder();
+	    boolean underscore = false;
+	    for ( char ch : aSnake.toCharArray() ) {
+	        if ( Character.toString(ch).equals(UNDERSCORE) ) {
+	            underscore = true;
+	        } else if ( underscore ) {
+	            camel.append(Character.toUpperCase(ch));
+	            underscore = false;
+	        } else {
+	            camel.append(ch);
+	        }
+	    }
+	    return camel.toString();		
+	}
+	
+	private static final String SPACE = " ";
+	private static final String UNDERSCORE = "_";
+	private static final String HYPHEN = "-";
+	
+}