JQuery/JavaScript - highlight a part of text from input or textarea [duplicate]

Answer 1

This code snippet shows you how:

window.onload = function() {
    var message = document.getElementById('message');
    // Select a portion of text
    createSelection(message, 0, 5);

    // get the selected portion of text
    var selectedText = message.value.substring(message.selectionStart, message.selectionEnd);
    alert(selectedText);
};

function createSelection(field, start, end) {
    if( field.createTextRange ) {
        var selRange = field.createTextRange();
        selRange.collapse(true);
        selRange.moveStart('character', start);
        selRange.moveEnd('character', end);
        selRange.select();
    } else if( field.setSelectionRange ) {
        field.setSelectionRange(start, end);
    } else if( field.selectionStart ) {
        field.selectionStart = start;
        field.selectionEnd = end;
    }
    field.focus();
}