Welcome to stackoverflow! What you need to know is that a key is unique in a map object. You have only two keys which are true and false. So, if you try to insert into the map a key that already exists, then it will be updated with the new key/value pair you are setting. This is why you only see two key/value pairs as output. Also as a little side-note when you declare values of array1 since you are working with a single element in each iteration of the loop it would be better to have value of array1 to make the code a little more cleaner.

Since map key is unique, so you got only two keys. If you want to get maps for each values, you can make a pair of key and value and then insert it into an array.

const array1 = [1,0,1,0,1,-1];

let result = [];
for (values of array1 ) {
    if (values !== 0) {
        const mapExample = new Map(); 
        mapExample.set(true, values)
        result.push(mapExample)
    } else {
        const mapExample = new Map(); 
        mapExample.set(false, values)
        result.push(mapExample)
    }
}

console.log(result)

the result would be like this

[
  Map(1) { true => 1 },
  Map(1) { false => 0 },
  Map(1) { true => 1 },
  Map(1) { false => 0 },
  Map(1) { true => 1 },
  Map(1) { true => -1 }
]