Why +[] or +"" equal to 0 in javascript

 

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  • Why does ++[[]][+[]]+[+[]] return the string “10”? 8 answers

    • Because empty string ("") is false in javascript (As Javascript is a dialect of ECMAScript, and ECMAScript language specification clearly defines this behavior) and + unary operator converts false to 0 .

    Reference : http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf

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