Flowchart
A flowchart is a programming tool that uses arrows and symbols to show the order of execution of the programmer’s statements. While drawing a flowchart one is not concern with the details of a programming language so one can concentrate on the logic of the program. In addition, it is easier to detect errors in case of a flowchart as flow of operations is represented in a pictorial form.
A program’s flowchart is like a blue print of a building. As designer draws a blueprint before starting a construction similarly a programmer prefers to draw a flowchart before making a program. Most of the programmers begin designing a complex program by first designing its flowchart. Once the proper flowchart has been developed, the programmer forgets about the logic and can concentrate on designing the code of the programs. We shall now discuss the various symbols used in drawing flowcharts.
- Terminal symbol: It is used to mark the start, end or pause in a flowchart. As this symbol is used to mark the start of the flowchart then the word START is written inside it. When it is used to mark the end of the flowchart then the word STOP is written inside it.
- Input/output symbol: It denotes the input/output operations in a flowchart. All the input/output variables are written in it.
- Diamond symbol: It is a diamond symbol. All the decision statements are enclosed in it. It receives one input and may branch to one of the possible alternatives depending on the decision made. Some decision statements may even branch out in three possible alternatives depending on the decision made. Some decision statements may even branch out in three possible alternatives or even multiple possible alternatives. For example: if a decision involves comparing of two numbers x and y then there may be three possible alternatives. a. When x>y b. when x=y c. when x
- Processing symbol: All the instructions are represented using the processing symbol(a rectangle). These instructions include the arithmetic and logical instructions. The instructions are written inside the rectangle.
- Flow lines: The flow lines are lines with arrow heads which indicate the flow of operations. Generally, the flow in case of a flow chart is from top to bottom and from left to right. One should make sure that the flow lines should not cross or intersect each other.
- Connector symbols: They are used to mark the entry from or exit to another part of a flowchart. A connector symbol is indicated by a circle with a letter or digit to indicate a link. They don’t represent any operation. They are just added for the sake of clarity.
Advantages of flowcharts:
The following are some of the advantages of flowchart using as a tool for programming planning:- Flowchart helps to explain the logic of program in a much better way than other techniques.
- Flowchart is an effective tool in detecting, locating and removing errors in a program.
- Flowchart provides documentation support which is very helpful in designing a good program.
- Flowchart help in designing error free and efficient programs.
- After develop a flowchart the programmer can concentrate on the designing of the code rather than logic.
Disadvantages of flowcharts:
Despite many advantages, flowcharts also possess certain limitations. These limitations are:- It is very difficult to draw flowcharts for large and complex programs involving a large number of statements.
- It is very difficult to incorporate changes in a flowchart as it is difficult to manipulate symbols used.
- No standard exist that could determine the amount of details that could be added to a flowchart.
- It is very difficult to reproduce a flowchart.
- It takes lot of space.
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