Spire.Cloud.Word provides the ReplaceApi interface, which is used for replacing old strings in Word documents with new strings. This article demonstrates the same.

using System;
using Spire.Cloud.Word.Sdk.Api;
using Spire.Cloud.Word.Sdk.Client;

namespace ReplaceText
{
    class Program
    {
        static String appId = "App ID";
        static String appKey = "App Key";
        static string basePath = " https://api.cloudxdocs.com";

        //Create a Configuration object based on App ID and App Key
        static Configuration wordConfiguration = new Configuration(appId, appKey, basePath);

        //Create a ReplaceTextApi object
        static ReplaceTextApi replaceTextApi = new ReplaceTextApi(wordConfiguration);
        static void Main(string[] args)
        {
            //Specify the source document name
            string name = "sample.docx";

            //Specify the text to be replaced
            string oldValue = "Spire.Doc";

            //Specify new text that'll be replaced in
            string newValue = "SPIRE.DOC FOR .NET";

            //Specify the path and name of the generated document
            string destFilePath = "output/ReplaceWithText.docx";

            //Specify the open password of the source document, set to null if there’s no password
            string password = null;

            //Specify the folder where the source document is stored
            string folder = "input";

            //Use the default storage, set to null
            string storage = null;

            //Specify whether it is case sensitive
            bool? matchCase = false;

            //Specify whether it will match the whole word
            bool? matchWholeWord = true;

            //Specify whether it will only replace the first text
            bool? replaceFirst = false;

            //Call ReplaceWithText method to replace old text with new text
            replaceTextApi.ReplaceWithText(name, oldValue, newValue, destFilePath, password, folder, storage, matchCase, matchWholeWord, replaceFirst);
        }
    }
}