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Javascript – RegExp variable gives boolean result, but giving variable name in array instead of boolean value

I need an array with the boolean values, but instead, it gives me the variable name.

Here is a simplistic example:

I declare variable to check for match to other data, gives boolean results.

var usatest = new RegExp("USA").test(continent);  //this gives true result
var canadatest = new RegExp("Canada").test(continent); //this gives false result
var mexicotest = new RegExp("Mexico").test(continent); //this gives false result

create array from the variables:

var testArray = 'usatest,canadatest,mexicotest'.split(",");

so testArray is ['usatest','canadatest','mexicotest'] but want [ true, false, false ]
tested other ways:

var testArray1 = [{}];
testArray1[0] = usatest; 
testArray1[1] = canadatest;
testArray1[2] = mexicotest;

result is array [ true , false, false].

So try to substitute the name with the array value (would allow me to use a for loop for a long list)

var testArray2 - [{}];
testArray2[0] = usatest;
testArray2[1] = testArray1[1];
testArray2[2] = testArray1[2];

would expect to get [ true, false, false] but get [true , 'canadatest', 'mexicotest']

why does using testArray1[1] in the second array return the variable name and not the boolean value? And maybe that will answer why testArray does not return boolean values either. What am I missing?

Thanks,
Doc

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2

Answers


  1. 0

    For your first attempt, testArray is the result of a String.split operation, so of course it’s an array of strings.

    For your third attempt: Are you sure you used the correct array to get your data from, because testArray1[1] is a boolean, there is no way, that testArray1[1] will give you canadatest

    The simplest in your usecase is possibly (assuming continent is defined accordingly)

    let arr = ["USA", "Canada", "Mexico"].map(x => new RegExp(x).test(continent))

    Ie, create an array from the results of the RegExp.test function directly …

    Dynamically access to variables (ie when their name is stored in another variable) is a real pain in JS, especially if they are not living in the global window context.

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  2. 0

    I think you can correct this step
    create an array from the variables:

    var testArray = [usatest, canadatest, mexicotest];

    enter image description here

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