WEBVTT

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In this video we're going to learn javascript errors.

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OK let's run a piece of code that we know is going to give us an error.

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So if we use a function some that we have not defined and some of three and four.

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OK.

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And if we run that we have a look at the console.

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We're going to see an error message.

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Sum is not defined.

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OK so now we want to find a way of getting this error message and then using it to change the value

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of a of any Shamal element for example.

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OK so what are you going to need.

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We will need a try statement.

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So basically the Troy statements will allow us to use or to execute a piece of code and test it for

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errors.

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Ok so the syntax is Troy followed by the code to be executed in curly brackets.

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In our case we want to test this line of code.

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OK.

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And then we're going to need another statesman's.

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It's a catch statesman's.

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So basically if an error happens in the try block then this is going to be the code to execute.

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If there's an error.

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So the syntax is by using the keyword catch.

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OK.

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And then between parentheses we need to put the variable air e r r.

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OK.

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And then follows the piece of code to be executed if there is an error.

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So what we would like to do here is to display the error message inside a paragraph.

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So let's create a paragraph

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OK and give us an ID of error.

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Also we want to style this paragraph.

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So when you leave a space changed color to something red it is.

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It's this color for example.

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OK.

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And the code to be executed if there is an error.

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So we want to change the contents of the paragraphs so the documents gets elements by id error and we

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want to change the a shemale to the error message.

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So this variable is an objects and one of its properties is message which is the message is displayed

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here.

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OK so we need to set the Ishmail to air Dot's message.

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OK.

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So let's try it now and we can see that the sum is not defined in the paragraph