I want to return tooltip single value which is in array.Valid value should be display on tooltip.

columnValue =["qqqw","wtye"]

    if (columnValue) {
      if (columnValue.new !== columnValue.old) {
        const newVal = columnValue.new ? columnValue.new.toString().toUpperCase() : '';
        const oldVal = columnValue.old ? columnValue.old.toString().toUpperCase() : '';
        columnValue = oldVal !== newVal ? oldVal + '\n' + newVal : newVal;
        console.log(columnValue);
      } else if(Array.isArray(columnValue)){
        var columnValue1=columnValue;
        columnValue1.forEach(value=>{
         columnValue =value
      }) 
      }
    }
    return columnValue;
  }


I want to show only single value when I mouse hover on 'qqqw'.Now it is displaying only 'wtye'
Because of final columnValue of forEach is last index.

Please help me!!!