replace.js

/**
 * Replace {0} in message. Credits: @Haixing-Hu
 *
 * @param template
 *    the message template, which contains zero or more placeholders, e.g.,
 *    "{0}", "{1}", ...
 * @param arg1, arg2, ...
 *    zero or more arguments used to replace the corresponding placeholders
 *    in the message template.
 * @return
 *    the formatted message.
 * @author Haixing Hu
 */

var PLACEHOLDER_REGEXP = /\{([0-9a-zA-Z]+)\}/g;

module.exports = function() {
    if(arguments.length === 0) {
        return ""
    }else if(arguments.length === 1) {
        return arguments[0]
    }else{
        var args = arguments
        var message = args[0]
        return message.replace(PLACEHOLDER_REGEXP, function(match, placeholder, index) {
            if (message[index - 1] === "{" && message[index + match.length] === "}") {
                return placeholder;
            }else{
            var i = parseInt(placeholder)
            var result = args[i + 1]
                if (result === null || result === undefined) {
                    return ""
                }else{
                    return result
                }
            }
        })
    }
}