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console.log(true+true); //2
console.log(typeof(true+true)); //number
console.log(isNaN(true+true)); //false
Why is adding together 2 boolean types yielding a number? I kind of understand that if they didn't equal (1/0 (binary?)) it would be awkward to try to perform arithmetic on a boolean type, but I can't find the reasoning behind this logic.
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Because you can't add booleans, so it converts them to numbers first.
To add a Boolean attribute: node. setAttribute(attributeName, ''); // example: document. body.
append accepts only a USVString or a Blob . S you will have to convert your data to string and then parse it later on the backend. You can use JSON. stringify to convert your form object to a string.
JavaScript provides the Boolean() function that converts other types to a boolean type. The value specified as the first parameter will be converted to a boolean value. The Boolean() will return true for any non-empty, non-zero, object, or array.
It works like that because that's how it's specified to work.
EcmaScript standard specifies that unless either of the arguments is a string, the + operator is assumed to mean numeric addition and not string concatenation. Conversion to numeric values is explicitly mentioned:
Return the result of applying the addition operation to ToNumber( lprim) and ToNumber(rprim).
(where lprim and rprim are the primitive forms of the left-hand and the right-hand argument, respectively)
EcmaScript also specifies the To Number conversion for booleans clearly:
The result is 1 if the argument is true. The result is +0 if the argument is false.
Hence, true + true effectively means 1 + 1, or 2.
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