对于文本<input>元素，将执行以下操作。该示例在输入中仅选择单词“ two”：

function setInputSelection(input, startPos, endPos) {

    input.focus();

    if (typeof input.selectionStart != "undefined") {

        input.selectionStart = startPos;

        input.selectionEnd = endPos;

    } else if (document.selection && document.selection.createRange) {

        // IE branch

        input.select();

        var range = document.selection.createRange();

        range.collapse(true);

        range.moveEnd("character", endPos);

        range.moveStart("character", startPos);

        range.select();

    }

}



document.getElementById("setSelection").onmousedown = function() {

    var input = document.getElementById("i");

    setInputSelection(input, 4, 7);

    return false;

};


<input id="i" type="text" value="One two three">

<input type="button" value="Set selection" id="setSelection">