<script type="text/javascript">
var str="/Date(1557773240026)/"
function ChangeDateFormat(timestamp) {
var date = new Date(parseInt(timestamp.replace("/Date(", "").replace(")/", ""), 10));
Y = date.getFullYear() + '-';
M = (date.getMonth() + 1 < 10 ? '0' + (date.getMonth() + 1) : date.getMonth() + 1) + '-';
D = (date.getDate() < 10 ? '0' + (date.getDate()) : date.getDate()) + ' ';
h = (date.getHours() < 10 ? '0' + (date.getHours()) : date.getHours()) + ':';
m = (date.getMinutes() < 10 ? '0' + (date.getMinutes()) : date.getMinutes()) + ':';
s = (date.getSeconds() < 10 ? '0' + (date.getSeconds()) : date.getSeconds());
return Y + M + D + h + m + s;
}
console.log(ChangeDateFormat(str))
</script>