Javascript The Bad Parts: Plus Operator

As you may know JavaScript has some of the best features that modern programming languages can offer, however it also has some really terrible parts. This is going to be a series of short posts about those terrible parts. My intention is to shed some light on these problems and help you mitigate or avoid them entirely.

I will start of with my personal favorite – plus operator. JavaScript has this terrible design flaw – plus operator is overloaded. Meaning that it can have two distinct behaviors depending on the situation. The same operator can both add and concatenate. Let me give some examples of this weird behavior:

Basically, when you mix numbers with strings bad things start to happen. In order to avoid problems with addition and concatenation try to ensure that all of your operands are of the same type: numbers or strings. This will ensure that the plus operator is working in the expected mode and will not switch in the middle of you operation.

Thank you for reading, everyone.

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