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78 lines
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1.8 KiB
Markdown
78 lines
No EOL
1.8 KiB
Markdown
# Lecture for March 13th
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## Methods
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Methods are small blocks of statements that make it easier to solve a problem. It usually focuses on solving a small part of the overall problem.
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Usually in methods you provide some sort of input and get some output out of it.
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### Advantages
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- Code readability
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- Modular program development (break up the problem in chunks)
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- Incremental development
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- No redundant code!
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### Method definition
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Consists of a method name, input and output and the block of statements.
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Usually this is succinctly written using JavaDocs which is what you see in the JavaAPI
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### Method Call
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A method call is the execution of the method. The statements defined in the method is what will execute.
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### Method Stubs
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Recall from method definition the parts of the method definition. Now look at the following method
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```java
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String[] split(String s)
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```
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The output here is `String[]`
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The method name is `split`
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The input is `String s`
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## Modular Programming
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Let us look at the following example:
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The program should have a list of grocery prices. It should be able to calculate the total cost of groceries. The store gives a student discount of 5%. The program should calculate this discount and update the total, it should calculate and add the 2.5% tax.
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- First you should add it all up
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- Then compute the discount
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- Then add the tax
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## Parts of a method definition
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```java
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public static int timesTwo(int num) {
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int two = num * 2;
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return two;
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}
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```
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It first starts off by declaring the visibility `public`
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The return type if `int`
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The method name is `timesTwo`
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The input parameter is `int num`
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Between the curly braces is the *body* of the method
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## Calling a Method
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```java
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int a = 5;
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int b = 3;
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int ans = multiply(a, b)
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```
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The method call is `multiply(a, b)` and the result is stored in the variable `ans` |