JS variables are cleared - Stack Overflow

Question

The variables in the code were cleared inexplicably, as shown in the figure below:

code show as below:

function rolldiceSumProb(arr, sides){

    let prob, result=[];
       
    let dig = function(target, count, methods) {

        if (count > sides) return false

        console.log('dig', target, count)

        for (let i=1; i<=6; i++) {

            console.log('target:', target, 'count:', count, 'cur_i:', i, target+i==arr, sides==count)

            if (target+i==arr && sides==count) {

                methods.push(i)
                result.push(methods)
                console.log(methods, result, 'quit')
                methods.pop()
                return false
            }
            else {

                methods.push(i)
                if (target+i < arr) dig(target+i, count+1, methods)
                methods.pop()
            }
        }

    }

    dig(0, 1, [])

    console.log('res', result)

    return prob;

}

rolldiceSumProb(11, 2)

Answer 1

methods has always been the same one... Although it has been added to result, it is only an added reference, not a copy. So you can add a copied result, such as

result.push([...methods]);

Or use es5 syntax

result.push([].concat(methods));

Answer 2

What you pass into the result is a reference to the method. If you clear the method, the result will naturally have no value. You need to copy the method and pass it into the result.