Javascript function call from file -


so...my homework says...

create function named calcbmi() performs calculation using values in weight , height text boxes , assign result bmi text box. convert value integer number using parseint() function. reference text boxes within function using documentobject.getelementbyid(name), , value attribute of each text box (in other words, don’t use function arguments aka pass values function). add event listener to call calcbmi() function

i have done here. keep in mind javascript file being reference in html. whenever press calculate button nothing happens. 

  function calcbmi() {       var weight = parseint(documentobject.getelementbyid("weight"));      var height = parseint(documentobject.getelementbyid("height"));      var result = (weight * 703) / (height * height);      var textbox = documentobject.getelementbyid('result');      textbox.value = result; }    document.getelementbyid("submit").       addeventlistener("click", calcbmi(), false);

i see 3 things:

  1. accessing dom object rather value
  2. using documentobject rather document
  3. invoking function instead of passing callback.

here's resolve dom element issue:
var weight = parseint(document.getelementbyid("weight").value)
use same other variables.

it looks may invoking calcbmi() rather passing callback calcbmi
.addeventlistener("click", calcbmi, false);

check out mdn on event listeners

it looks referencing documentobject rather document.

var textbox = documentobject.getelementbyid('result');

try this:
var textbox = document.getelementbyid('result');

hope helps!


Comments

Post a Comment

Popular posts from this blog

angular - Ionic slides - dynamically add slides before and after -

hi i'm using ngfor create set of 3 slides while starting in middle i'm guaranteed able slide left or right on start. when slide right can simple listen reachedend , push slide array i'm looping. but have problem adding slide beginning. if same above , use e.g. array.unshift() or spread add item beginning, view think it's on position 0 , snaps view new slide. the code below work animates slide change index 1. slide = [0,1,2] //example loop slidechanged(event) { if(this.slides.isbeginning()){ this.slide = [this.slide[0]-1, ...this.slide]; this.slides.update(); this.slides.slideto(1) } } <ion-slides [initialslide]="1" (ionslidedidchange)="slidechanged($event)"> <ion-slide *ngfor="let item of slide"> <h1>slide {{item}}</h1> </ion-slide> </ion-slides> any appreciated! you can using ionslidenextend , ionslideprevend events slides . please
Read more

minify - Minimizing css files -

i want know how css files can minimized. currently, using external sites css minifier compress css files. however, after removing whitespaces, comments, etc, file sizes reduced 10-15%. how frameworks bootstrap manage make minimized versions kilobytes. as example, css is: body { background-color: #ff0; } the reduction goes 28 bytes 22 bytes other css files have lot more characters still smaller this. actually minifying code means it's remove thing code white space characters new line characters comments block delimiters it reduces amount of code has transferred on web , speed site load fastly.but unreadable format.
Read more

Add a dynamic header in angular 2 http provider -

i have http interceptor built via tutorial https://scotch.io/@kashyapmukkamala/using-http-interceptor-with-angular2 the problem need have dynamic header changes automatically once changes 'mode' in app. service able tell interceptor change header, or have interceptor pull header (which string)from service each request. able throwing away patch method, call http.patch('new header string') set header string. call in service controls 'mode' setting. wondering if there way interceptor pull recent value service each request or if can add method http provider via interceptor? i've tried call service in interceptor each request returns undefined. because creating new instance of service or copying value before service fired , loaded/changed data. i don't want pass header string every http provider call because defeats purpose of having interceptor, id able set once changes or have provider fetch service before makes request. tl;dr : need add autom
Read more