Javascript Concatenation -


this question has answer here:

i came across following snippet of codes in javascript quiz online. not understand how concatenation works in js. can 1 explain how works ?

[] + [] = ""    // output : ""  [] + [] + "foo" // output : "foo"

javascript tries apply + operator in different ways, it's been taught to.

so unless explicitly told, calls tostring method of array it's best guess when it's told add 2 arrays.

[] + [] = ""  +[] + [] = "0"    // if give hint cast 1 of array number  +[] + +[] = 0     // if give hint cast both arrays number

while [] + [] + "foo" 

([] + []) + "foo" = "" + "foo" = "foo"

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