How to Handle Errors in JS with try/catch

What is a try/catch in JavaScript?

A try/catch is basically used to handle errors in JavaScript. You use this when you don’t want an error in your script to break your code.

try/catch block statements

1. trow error statement

But we can take it a step further by actually throwing an error with the JavaScript constructor errors.

Actually, JavaScript categorizes errors into six groups:

• EvalError — An error occurred in the eval function.
• RangeError — A number out of range has occurred, for example 1.toPrecision(500). toPrecision basically gives numbers a decimal value, for example, 1.000, and a number cannot have 500 of that.
• ReferenceError — Using a variable that has not been declared
• syntax error — When evaluating a code with a syntax error
• TypeError — If you use a value that is outside the range of expected types: for example 1.toUpperCase()
• URI (Uniform Resource Identifier) Error — A URIError is thrown if you use illegal characters in a URI function.

The Finally statement

The finally statement acts like neutral ground, the base point, or the final ground for your try/ catch block. Finally, you are basically saying no matter what happens in the try/catch (error or no error), this code in the finally statement should run.For example:

let data=prompt("name")
try{ 
if(data==="") throw new Error("data is empty") 
else alert(`Hi ${data} how do you do today`) 
} catch(e){ 
alert(e) 
} finally { 
alert("welcome to the try catch article")
}

Conclusion

In this article, I have tried to explain the following concepts relating to try/catch:

• What try /catch statements are and when they work
• How to throw custom errors
• What the final statement is and how it works
• How Nesting try/catch statements work
• How to rethrow errors