Being new to JavaScript, I have come across information stating that the value of this changes based on how a function is invoked. However, I am confused about when it is necessary to use this and when it is not. Some code examples I've seen utilize this, while others do not.
For example, consider this function with a for loop that does not utilize this:
var output="";
for(var i=0; i<input.length; i++) {
output = input.charAt(i) + output;
}
return output;
This can be quite a confusing concept in the world of JavaScript. While there are no strict rules dictating when you must use this, it does come in handy in certain scenarios.
Check out this resource from Mozilla Developer Network on this
Oftentimes, the value assigned to
thisis dependent on how a function is called. It cannot be altered during execution and may vary each time the function is invoked.
For a deeper understanding of JavaScript's "this," consider reading this article: Understand JavaScript’s “this” With Clarity, and Master It
An example where the use of this is almost always necessary is when working with an ES5 constructor. By assigning properties to the constructor using this, they become object properties on the newly created instance.
function Person(name) {
this.name = name;
}
var me = new Person('yourname');
me.name // 'yourname'
Here's an example of what the object looks like: informations = { addresses: { 0: {phone: 0}, 1: {phone: 1}, 2: {phone: 2}, 3: {phone: 3}, 4: {phone: 4}, 5: {phone: 5}, }, names: { 0 ...
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