SOURCE

let data=[{label: '默认'}, {label: '默认1'}, {label: '默认2'}]
function getLabel(label) {
    let last = label[label.length - 1];
  while (data.find(a => a.label === label)) {
    if (!isNaN(last)) {
        console.log('in', last, label)
      last = Number(last) + 1;
      label = label.substr(0, label.length - 1) + last
    } else {
        label = label + '1';
    }
    last = label[label.length - 1];
  }
  return label;
}