JSFiddle - React, Tailwind, and code Playground

JavaScript

function execStringFn(str, onObject) {
    var matchFnName = /^([^(]+)\(([^)]+)\)/.exec(str);
    if (matchFnName) {
        var fnName = matchFnName[1];
        var paramListStr = matchFnName[2];
        var paramList = paramListStr.split(',');
        if (!onObject) onObject = this;
        onObject[fnName].apply(onObject, paramList);
    }
}

execStringFn('alert(\'foo\')');