I'm facing a if condition issue in javascript. Please have look on below code.

1.

const a = 1;
if(a && a > -1)
{ 
console.log('suceess')
} 
else
{ 
console.log('failed')
}

Here in if condition it is returning true.

2.

const a = 0;
if(a && a > -1)
{ 
console.log('suceess')
} 
else
{ 
console.log('failed')
}

Here in if condition it is returning Zero.

I'm not getting this. Can someone please explain why is it so.