how to increase font size in UIWebView

Question

how to increase or decrease the UIWebview font size, not using scalePageToFit:NO;

Answer 1

in my case im using a UISlider for the fontSize, can be any float value

func webViewDidFinishLoad(_ webView: UIWebView) {

    if let fontSize: Float = (self.fontSizeSlider?.value) {
        webView.stringByEvaluatingJavaScript(from: "document.getElementsByTagName('body')[0].style.webkitTextSizeAdjust= '\(fontSize)%%'")
        print(fontSize)
    }

}