I want to merge this array using or || operator

[[true,false,false],[false,false,false],[false,false,true]]

so that the output is

[true,false,true]

is this possible with map or reduce or similar?

Edit: Sorry for the unclear question - yes it was to vertically merge all sub arrays together. So the following input:

[[true,false,false],[false,false,false],[false,false,true],[false,false,true]]

would produce the same output:

[true,false,true]

I want to merge this array using or || operator

[[true,false,false],[false,false,false],[false,false,true]]

so that the output is

[true,false,true]

is this possible with map or reduce or similar?

Edit: Sorry for the unclear question - yes it was to vertically merge all sub arrays together. So the following input:

[[true,false,false],[false,false,false],[false,false,true],[false,false,true]]

would produce the same output:

[true,false,true]

• javascript
• arrays

• 1 What is the logical condition for merging? – brk Commented Sep 9, 2017 at 15:17
• 2 1. Do you want that first true to be a[0][0] || a[0][1] || a[0][2] or a[0][0] || a[1][0] || a[2][0]? 2. What have you tried to solve the problem? – T.J. Crowder Commented Sep 9, 2017 at 15:21
• 1 Well, thanks to the unclear question, you now have answers both ways. :-) marvel308's if you want the first one, Nina's if you want the second. – T.J. Crowder Commented Sep 9, 2017 at 15:21
• To put TJ's observation in another way, are you merging vertically or horizontally? Are you merging each array or are you merging value at an index across all arrays? – vol7ron Commented Sep 9, 2017 at 15:27

3 Answers 3

You don't really need the || when you use some:

var array = [[true, false, false], [false, false, false], [false, false, true]];

var result = array[0].map( (_, i) => array.some(a => a[i]));

console.log(result);

You could reduce the arrays with mapping the same index values.

var array = [[true, false, false], [false, false, false], [false, false, true]],
    result = array.reduce((a, b) => a.map((c, i) => b[i] || c));

console.log(result);

you can do it in the following way

let arr = [[true,false,false],[false,false,false],[false,false,true]];

arr = arr.map(function(element){
    return element.reduce(function(a, b){
        return (a|b);
    })
})

console.log(arr);