Today I got a chance to present on three topics during the “System Analysis and Design” course mode of my MSc in IT course. It was very interactive during the presentations. So I would like to share the presentations on the topics.. I would like to thank my lecturer Mr. Chaman Wijesiriwardane for giving me the opportunity.
Showing posts with label Best Practice. Show all posts
Showing posts with label Best Practice. Show all posts
Saturday, November 29, 2014
Saturday, April 19, 2014
How to prevent from declaring global variables in JavaScript?
Introduction
When we declare a variable in JavaScript; if its declared with the var keyword it will be a local variable and if we omit the var key work it will be implicitly declared as the global variable. Developers are always careful on creating global variables.
Problem Background
Developers may accidentally declare global variable without their knowledge.
Conclusion
If we use strict method; when we debug we will get an exception on the line where we have declared global variables. See the screenshot below.
When we declare a variable in JavaScript; if its declared with the var keyword it will be a local variable and if we omit the var key work it will be implicitly declared as the global variable. Developers are always careful on creating global variables.
Developers may accidentally declare global variable without their knowledge.
Solution
- function funcationName() {
- "use strict";
- };
To avoid developers from creating global variable you can use strict mode as given below. .
Conclusion
If we use strict method; when we debug we will get an exception on the line where we have declared global variables. See the screenshot below.
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