vara=[{a:1,b:2,c:3},{a:4,b:5,c:6}]
Object.keys(a[0]).map(l=>[l,...a.map(e=>e[l])])
                            

varsource=[{a:1,b:2,c:3},{a:4,b:5,c:6}]
vartarget=[]
varstore={}
for(vari=0;ivarobj=source[i]
for(varkeyinobj){
if(store[key]){
store[key].push(obj[key])
}else{
store[key]=[obj[key]]
}
}
}
for(varkinstore){
store[k].unshift(k)
target.push(store[k])
}
console.log(target)