complete_rhombus-star_structure

let i, j, k;
let l = 1;
let rows = 51; // 
let topPyramid = parseInt(rows/2 + (rows%2));
let spaceSec2 = 1;
let lDown = rows - 2;
let s = '';
for(i = 1; i <= rows; ++i){
    if(i <= topPyramid){
        for(j = i; j < topPyramid; ++j){
            s+=' ' + ' ';
            
        }
        for(k = 1; k <= l; ++k){
            s+='* ';
        }
        l+=2;
    } else {
        for(j = 1; j <= spaceSec2; ++j){
            s+=' '+' ';
        }
        for(k = 1; k <= lDown; ++k){
            s+='* ';
        }
        ++spaceSec2;
        lDown-=2;
    }
    console.log(s);
    s= '';
}