javascript - How to do math with an array (add +1) -

i have value in input this:

7*7*0*0*32*17 

i simple .split('*') obtain following arrays:

["7","7","0","0","32","17"] 

then transform arrays numbers .map(number), arrays composed not of strings numbers:

[7,7,0,0,32,17] 

what interests me second 7. use .slice(1,2) in order select alone. until point, works:

[7] 

my problem is, can't add +1 transform 7 8. instead, returns 71.

let's call array of ["7","7","0","0","32","17"] -> "myarray" simplify whole stuff.

console.log(myarray); var myarraymapped = myarray.map(number); console.log(myarraymapped); var myarraysliced = myarraymapped.slice(1,2); console.log(myarraysliced); var myarrayincreased = myarraysliced + 1; console.log(myarrayincreased); 

and here results of console.logs:

["7","7","0","0","32","17"] [7,7,0,0,32,17] [7] 71 

everything works expected until line, doesn't work:

var myarrayincreased = myarraysliced + 1; 

note final goal put 8 inside input, , reconstruct array 1 single string below, maybe there's simplier , faster solution haven't seen. basically, button call function add +1 specific part of value want select (the second "7"):

from:

7*7*0*0*32*17 

to:

7*8*0*0*32*17 

thanks in advance. note not want sum arrays, nor push new array among ones got (which topics i've seen through research, don't me). want maths 1 specific array.

instead of using slice, select it's array index

myarraymapped[1] += 1; 

which make final code

var myarray = ["7","7","0","0","32","17"]; console.log(myarray); var myarraymapped = myarray.map(number); console.log(myarraymapped); myarraymapped[1] += 1; console.log(myarraymapped);