display first element of list of string in visualforce

You can pass 0 at index of list as:

public List<String> listOfStrings {get;set;}
<h4>{! IF(listOfStrings.size > 0, listOfStrings[0], '') }</h4>

You can use regular "array" notation to show the first element. Be sure to check to make sure the list is neither null nor empty before trying to access an array element.

{!listOfStrings[0]}

Alternatively, you can use a repeat element:

<apex:repeat value="{!listOfStrings}" var="varString" rows="1">{!varString}</apex:repeat>

Obviously, this is a bit more verbose, but works all the same.

Finally, you can also simply use a getter method in Apex Code:

public String getFirstString() {
    return listOfStrings != null && listOfStrings.size() > 0? listOfStrings[0]: null;
}

Which is then used as:

{!firstString}

@Walker Here I have tried to create a VF page and a Controller as explained by sfdcfox and Ashwani above. Hope this helps.

VF Page

<apex:page showHeader="true" sidebar="true" controller="ListString">
    <h4>what expression to use {!listOfStrings[0]}</h4><br/>
    <h4>what expression to use <apex:repeat value="{!listOfStrings}" var="varString" rows="1">{!varString}</apex:repeat></h4><br/>
    <h4>what expression to use {!firstString}</h4><br/>
</apex:page>

Controller

public with sharing class ListString {
    public List<String> listOfStrings {get;set;}
    public ListString() {
        listOfStrings = new List<String>();
        listOfStrings.add('Hello');
        listOfStrings.add('World');
    }
    public String firstString {
        get {
            return listOfStrings != null && listOfStrings.size() > 0? listOfStrings[0]: null;
        }
        set;
    }   
}