Why such thing would happen in Javascript?
'5'+3 = 53
'5'-3 = 2
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10Because the language specification says so? – Frédéric Hamidi Jan 07 '15 at 10:26
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'5' is a string and + is used for string concatenation, so when using + with a string it will concatenate – Scriptable Jan 07 '15 at 10:28
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have you tried jquery? – atmd Jan 07 '15 at 10:29
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3@atmd What does this have to do with jQuery? – Ram Jan 07 '15 at 10:29
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Sorry, it was an attempt at humour – atmd Jan 07 '15 at 10:30
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possible duplicate of [this](http://stackoverflow.com/questions/26037997/why-is-number-string-a-string-in-javascript?lq=1) – anpsmn Jan 07 '15 at 10:32
2 Answers
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This is happening because + operator is overloaded. If any operand is a string, string concatenation is performed. If you have two numbers, addition is performed.
In other words
2+3=5
while '2'+3='23' and 2+'3'='23'.
On the other hand, for the - operator, it is not overloaded in such a way and all operands are converted to numbers.
'8'-2=6
because - is not overloaded and operand '8' will be converted to 8. Hence, we get 6.
For further information on this, please have a look here and read the paragraphs 11.6.1 and 11.6.2.
Christos
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String concatenation is done with + so Javascript will convert the first numeric 5 to a string and concatenate "5" and "3" making "53".
You cannot perform subtraction on strings, so Javascript converts the second numeric i.e. "3" to a number and subtracts 3 from 5, resulting in "2" as the result.
Shashank Vashist
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