什么是datalayer.push在做什么？

I've been trying to figure this out..I think data layer.push is simply updating the second amount. Could someone explain what is exactly going on here?

function dollarz() {
var amount1 = '$156.86';
var amount2 = amount1.replace("$","");
return amount2;
}

dataLayer.push({
'transactionTotalNoDollar': dollarz(),
'event': 'sendUpdateTwo'
});

dataLayer is presumably an array, and push adds an additional element to the end of the array.

The object that gets pushed has two properties: one is the static 'event': 'sendUpdateTwo'. The other property transactionTotalNoDollar gets its value from the result of calling dollarz. dollarz returns `'156.86', so the object that gets pushed looks like:

{ 
  'transactionTotalNoDollar': '156.86', 
  'event': 'sendUpdateTwo' 
}