Carry out the following steps to develop a Lightning Component, which is used for the user interface and grouping functional units, using the Salesforce Developer Console.

1. Click on the Setup gear icon, as shown in the following screenshot:

The Setup gear icon is located in the top right-hand area of the main Home page.

2. Click the Developer Console option, as shown in the following screenshot:

3. In the resulting Developer Console window, click on File.

4. Click on New.
5. Click on Lightning Component, as shown in the following screenshot:

6. In the resulting New Lightning Bundle dialog, enter accountSearchBeforeCreate in the Name textbox.
7. Enter This is a Lightning Component to display a Search dialog invoked from a New Account button override in the Description textbox.

8. Click on Submit, as shown in the following screenshot:

9. In the resulting Component page, paste the following code:

<aura:component controller="AccountSearchController" 
                implements="lightning:actionOverride, 
                force:hasRecordId, force:hasSObjectName"> 
  <!-- Attribute Declaration --> 
  <aura:attribute name="searchString" type="String" 
   description="Holds the User Search String Value"/> 
  <aura:attribute name="createStatus" type="boolean" 
   default="false" description="Holds the Status of 
   Records Returned"/> 
  <aura:attribute name="searchResult" type="List" 
   description="Holds the List of Accounts that is Returned"/> 
  <aura:attribute name="searchCounts" type="integer" default="0" 
   description="Holds the Count of Records Returned"/> 
  <!-- Search Section --> 
  <lightning:layout class="slds-page-header slds-page-header--
   object-home"> 
    <lightning:layoutItem > 
      <lightning:icon iconName="standard:account"
       alternativeText="Search Before Create"/> 
    </lightning:layoutItem> 
    <lightning:layoutItem padding="horizontal-small"> 
      <div class="page-section page-header"> 
        <h1 class="slds-text-heading--label">Account</h1> 
        <h2 class="slds-text-heading--medium">Search Before
         Create</h2> 
      </div> 
    </lightning:layoutItem> 
    <lightning:layoutItem padding="horizontal-medium">          
      <div class="slds-m-around--large"> 
        <form class="slds-form--inline"> 
          <div class="slds-form-element"> 
            <label class="slds-form-element__label" for="search">
            </label> 
            <div class="slds-form-element__control"> 
              <ui:inputText aura:id="searchId" class="slds-input"
               value="{!v.searchString}"  
               required="true" size="40"  
               placeholder="Search first before creating an
               account..."/> 
            </div> 
          </div>         
          <lightning:button label="Search" onclick="{!c.onSearch}"
            /> 
          <aura:if isTrue="{!v.createStatus}"> 
            <lightning:button class="slds-button--brand"
             label="Create" onclick="{!c.onCreate}" /> 
          </aura:if> 
          <aura:if isTrue="{!v.createStatus}"> 
            <div class="slds-text-color--error">No account records
             found, click on Create to create an account...</div> 
          </aura:if> 
        </form> 
      </div> 
    </lightning:layoutItem> 
  </lightning:layout> 
  <!-- Account Search Results --> 
  <aura:if isTrue="{!v.searchCounts>0}">     
    <div class="slds-m-around--large"> 
      <span class="slds-assistive-text">Number of Accounts
      {!v.searchCounts}</span> 
      <span class="slds-badge">Number of Accounts: {!v.searchCounts}
      </span> 
      <table class="slds-table slds-table--bordered slds-table--
      striped slds-table--cell-buffer slds-table--fixed-layout"> 
        <thead> <!-- SELECT Id, Name, Type, Industry, Description,
         Phone --> 
          <tr class="slds-text-heading--label"> 
            <th scope="col">
              <div class="slds-truncate" title="Id"></div>
            </th> 
            <th scope="col">
              <div class="slds-truncate" title="Account Name">
                Account Name</div>
            </th> 
            <th scope="col">
              <div class="slds-truncate" title="Type">Type</div>
            </th> 
            <th scope="col"><div class="slds-truncate"
              title="Industry">Industry</div></th> 
            <th scope="col"><div class="slds-truncate"
              title="Description">Description</div></th> 
            <th scope="col"><div class="slds-truncate"
              title="Phone">Phone</div></th> 
          </tr> 
        </thead> 
        <tbody> 
        <aura:iteration items="{!v.searchResult}" var="acc"
          indexVar="idx"> 
          <tr> 
          <!-- Allows the user to navigate to the account record --> 
            <td><div class="slds-truncate"  data-record="{!idx}"   
              onclick="{!c.onNavigate}" 
              onmouseover="" style="cursor: pointer;">
              [Navigate to account]</div></td> 
            <td><div class="slds-truncate">{!acc.Name}</div></td> 
            <td><div class="slds-truncate">{!acc.Type}</div></td> 
            <td><div class="slds-truncate">{!acc.Industry}</div>
            </td> 
            <td><div class="slds-truncate">{!acc.Description}</div>
            </td> 
            <td><div class="slds-truncate">{!acc.Phone}</div></td> 
          </tr> 
        </aura:iteration> 
        </tbody> 
      </table> 
    </div> 
  </aura:if> 
</aura:component>

10. Click on File.
11. Click on Save, as shown in the following screenshot: