Slice UF
HTML
<div id="print"></div>
JavaScript
var state = "RS - Rio Grande do Sul";
var uf = state.slice(0,2);
document.getElementById("print").innerHTML = uf;
<div id="print"></div>
var state = "RS - Rio Grande do Sul";
var uf = state.slice(0,2);
document.getElementById("print").innerHTML = uf;