Difference between revisions of "Assertions"

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(Created page with "== Introduction == * Assertions allow the testing of assumptions about a program. * Using assertions allow easy detection of bugs during development without writing exception h...")
 
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* Assertions allow the testing of assumptions about a program.  
 
* Assertions allow the testing of assumptions about a program.  
 
* Using assertions allow easy detection of bugs during development without writing exception handlers etc.
 
* Using assertions allow easy detection of bugs during development without writing exception handlers etc.
 +
* We "assert" that something will be true at some point in the code. If it is, code keeps running, if it is false, an AssertionError will be thrown.
 +
 +
Example:
 +
<syntaxhighlight lang="java5">
 +
 +
//Without assertions
 +
 +
private static void processAge1(int age) {
 +
if(age > 0) {
 +
System.out.println("Processing age ...");
 +
} else {
 +
System.out.println("Age < 0 !");
 +
}
 +
}
 +
 +
//With assertions
 +
 +
private static void processAge2(int age) {
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assert age > 0;
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System.out.println("Processing age ...");
 +
}
 +
 +
</syntaxhighlight>
  
  
 
[[Category:OCPJP]]
 
[[Category:OCPJP]]

Revision as of 01:46, 20 July 2011

Introduction

  • Assertions allow the testing of assumptions about a program.
  • Using assertions allow easy detection of bugs during development without writing exception handlers etc.
  • We "assert" that something will be true at some point in the code. If it is, code keeps running, if it is false, an AssertionError will be thrown.

Example:

//Without assertions

private static void processAge1(int age) {
		if(age > 0) {
			System.out.println("Processing age ...");
		} else {
			System.out.println("Age < 0 !");
		}
	}

//With assertions
	
private static void processAge2(int age) {
		assert age > 0;
		System.out.println("Processing age ...");
}