Main flowchart symbols

1. Start/End: A rounded terminal shows where the algorithm begins or finishes.
2. Input/Output: A parallelogram shows reading input or displaying a result.
3. Process: A rectangle shows a calculation or assignment, such as sum = a + b.
4. Decision: A diamond contains a condition. Its branches are labelled Yes/No or True/False.
5. Flow line: An arrow shows which step is followed next.
6. Connector: A small labelled connector joins parts of a chart when a long arrow would make it difficult to read.

Example: even or odd

Start by reading n. Test n % 2 == 0 in a decision diamond. If the answer is Yes, print Even. If it is No, print Odd. Both paths then reach End. For n = 8, the Yes path is followed. For n = 7, the No path is followed.

Advantages

A flowchart makes the order of steps easy to see. It is useful for explaining choices and loops. It also helps us follow the solution using sample values before writing the program.

Drawing rules

1. Use clear labels: Keep the text inside a symbol short and meaningful.
2. Label each branch: A decision must show which arrow is followed for each result.
3. Use arrowheads: The direction of execution must be clear.
4. Check every path: Make sure the steps reach a valid result or continue through a clearly shown loop.
5. Avoid crowding: Large flowcharts should be divided into smaller, understandable parts.

Reference table

Diagram or flowchart

Key points

• A decision chooses a path; a process changes or computes a value.
• Every arrow must have a meaningful destination.