How to assign existing option selected value in Lightning?

Question

I want to assign current selected option which is '0' and I want to assign it to '2' when URL is change. How can I do that? Please help.

Example.cmp

<div class="slds-col slds-size_1-of-5 slds-grid--vertical-align-start">
                <ui:inputSelect aura:id="mySelect" change="{!c.onChangeFunction}">
                    <aura:iteration items="{!v.options}" var="item" >
                        <ui:inputSelectOption text="{!item.label}" value="{!item.value}"/>
                    </aura:iteration>
                </ui:inputSelect>
                </div>

Example.js

component.set("v.options", [
            {'label': 'Default', 'value': 0, selected: "true"},
            {'label':'Yes','value':1},
            {'label':'No','value':2},]);

Example.helper

handleEvent :function(component,event,helper){  
        var sPageURL = decodeURIComponent(window.location); //get params from URL
        console.log('sPageURL' + sPageURL);
        const queryString = window.location.search;
        var option = component.find("mySelect").get("v.value"); //show undefined
},

Answer 1

I'm not sure if this is what you're looking for, but here's a demonstration of this technique:

<aura:application >
    <aura:handler name="init" action="{!c.init}" value="{!this}" />
    <aura:attribute name="options" type="List" default="[{'label':'Value 1','value':'1'},{'label':'Value 2','value':'2'}]" />
    <select aura:id="selection">
        <aura:iteration items="{!v.options}" var="option">
            <option value="{!option.value}">{!option.label}</option>
        </aura:iteration>
    </select>
    <div>Choose Value</div><aura:iteration items="{!v.options}" var="option">
    <div><a href="{!'#'+option.value}">{!option.label}</a></div>
    </aura:iteration>
</aura:application>

...

({
    init: function(component, event, helper) {
        window.addEventListener(
            'hashchange',
            $A.getCallback(function () {
                let sel = component.find("selection").getElement();
                let target = window.location.hash.substr(1);
                let index = [...sel.options].findIndex(option => option.value === target);
                sel.selectedIndex = index;
            })
        );
    }
})

...

We use the onhashchange event to detect URL changes, and then perform an update to the value based on that information.

Please that ui:inputSelect and ui:inputSelectOption (as well as all other "ui" elements) are deprecated, will stop working in the near future, and should not be used in any new code.