checking values before submitting form - javascript

Before I submit a form I want to check the values in the input.
Here I'm checking if a value is NOt equal to .5 or 1. or not a empty string.
form.onsubmit = function(e) {
var ftimes = document.getElementsByClassName("add_timebox");
var fflag = 0;
for(i=0;i< ftimes.length;i++) {
var value1 = ftimes[i].value;
console.log(value1);
if ( value1 !==.5 ||value1 !== 1 || (!IsStringEmpty(value1)) ){
fflag = 1;
console.log('inside');
}
}
if(fflag==1) {
alert('enter again' );
return false;
}
I have made many changes to the IF statement to try to get it correct.
But it is still going in the loop even when I know if shouldn't.
For example when i submit the form and i have one input value equal .22
then it should only give me 1 'inside' but in keeps repeating:
inside
.22
(empty string)
inside
....

You do not show how you are implementing your IsStringEmpty method, but if you are using something like this, then any number is also a non-empty string, so your if statement will always run.
function IsStringEmpty(str) {
return (!str || 0 === str.length);
}
So you need to change your ORs with ANDs, or it will never check the number conditions.
You can check if the value is not an empty string and is different from 0.5 and 1. Then your condition should be like this.
if (!IsStringEmpty(value1) && value1 !== 0.5 && value1 !== 1)
But, you are getting the value from a form, so it will be a string. Therefore, you are comparing strings and you need this.
if (!IsStringEmpty(value1) && value1 !== ".5" && value1 !== "1")
Although you will probably want to compare floats, in which case you need this.
if (!IsStringEmpty(value1) && parseFloat(value1) !== .5 && parseFloat(value1) !== 1))
So basically, when you enter 1, .5 or and empty string in all of the form fields, you skip the inside block. But if you have any other value in any of the fields, then the flag will be set to 1. If that is not what you meant, please update your question to be more specific.
Please check Plunker here.
Hope this helps.

you have to add a break; statment in your if condition once the if condition is satisfied.
if ( value1 !==.5 ||value1 !== 1 || (!IsStringEmpty(value1)) ){
fflag = 1;
console.log('inside');
break;
}

Related

issues with localStorage and saving values

I have a program where I have these strings being added to an array. However, there are many strings that are triggered by a certain condition, which can be met multiple times, however I only want it to be added on the first occurrence. So I have implemented a system where the event of adding the string to the array is triggered by the original condition, and a boolean expression. Here is an example of one of those conditions:
if (count >= 10 && displayMulti == true) {
consoleData.shift()
consoleData.push("Multi available")
displayMulti = false
window.localStorage.setItem("display_multi", String(displayMulti))
updateConsole()
}
When the string is added to the array, the boolean, displayMulti, is set to false so that it will not trigger again. However, upon refreshing the page, it will still trigger. I'm not sure why because I feel like I have saving the values to localstorage correctly. Code is below:
if (window.localStorage.getItem("display_multi") != null ) {
displayMulti = Boolean(window.localStorage.getItem("display_multi"))
} else {
console.log("here")
var displayMulti = true
}
There "here" console log statement is not triggered. So I have no idea why this would keep triggering because I don't see how the boolean is true. I've tested at like so many different points I genuinely have no idea what's wrong. I also don't think those values are affected anywhere else in my code. Any help is appreciated.
Here is a solution that properly parses your string as a boolean. Instead of Boolean(), a conditional (window.localStorage.getItem("display_multi") === 'true')(window.localStorage.getItem("display_multi") === 'true') is used.
if (window.localStorage.getItem("display_multi") != null ) {
displayMulti = (window.localStorage.getItem("display_multi") === 'true')
} else {
console.log("here")
var displayMulti = true
}
if (count >= 10 && displayMulti == true) {
consoleData.shift()
consoleData.push("Multi available")
displayMulti = false
window.localStorage.setItem("display_multi", String(displayMulti))
updateConsole()
}

if statement with more than one condition

I need to check three conditions,
sheet_exists = 1
recalc = 1
qty_total and new_qty_total are not equal
The if statement works well if only the first 2 arguments are used:
if(sheet_exists === 1 && recalc === 'yes'){
//do something
}
But when I try to add he 3rd argument it fails, the actions in the if statement are ignored. I've tried:
if((sheet_exists === 1) && (recalc === 'yes') && (qty_total !== new_qty_total)){
//do something
}
And:
if(sheet_exists === 1 && recalc === 'yes' && (qty_total !== new_qty_total)){
//do something
}
And:
if(sheet_exists === 1 && recalc === 'yes' && qty_total !== new_qty_total){
//do something
}
Where am I going wrong?
Considering you are happy with the behavior of the first two conditions, and not with the last one, the problem must be in the last one.
Pay attention, qty_total !== new_qty_total will return TRUE only when the value or type of qty_total and new_qty_total are different.
If one is an integer 100 and the other is a string '100' then the condition evaluates as TRUE because they differ on the data type. But if they are both integers it will return FALSE, because neither the value nor the type are different.
To make sure the comparison works ok, make sure both variables are the same data type.

test if two variables holds some data javascript

I define variables from two input fields - and wants to test if something was actually entered in both fields and then break if more than one field is filled.
I think the 'undefined' tricks me when setting the var's to .value - even though they don't contain data.
var value1 = document.getElementById('filegroup').value;
var value2 = document.getElementById('new_filegroup').value;
if(value1 !== undefined && value2 !== undefined )
{
alert("You must only fill one filegroup!")
return false;
}
Right now I'm being alerted even though I don't fill in anything.
Assuming document.getElementById('filegroup') is a form input of some type, the value will return a empty string when there is no value. Try:
var value1 = document.getElementById('filegroup').value;
var value2 = document.getElementById('new_filegroup').value;
if(value1 && value2) { // checks both values have something
alert("Both values have something")
}
if(value1 || value2) { // checks for at least one value
alert("one of them does")
}
N.B. if the values do come from a input, then a value of 0 will be a string, and seen as truthy. However the number 0 will be falsey.

Checking textbox if it's empty in Javascript

I wrote a simple html file with a textbox and submit button, and it generates and document.write's a response dependant on what you submit. I want to have it generate a response saying to enter content if the box is empty. The textbox's id is chatinput, so I have the following the code in the beginning
var chatinput_box=document.getElementById('chatinput');
var chatinput=chatinput_box.value;
Then a have a conditional, although I can't get it to work correctly; I've tried
if(chatinput==""){}
if(chatinput.length=0){}
if(chatinput=null){}
and others but none have worked correctly. Does anyone have another idea?
It should be this:
var chatinput = document.getElementById("chatinput").value;
if (chatinput == "" || chatinput.length == 0 || chatinput == null)
{
// Invalid... Box is empty
}
Or shorthanded:
if (!document.getElementById("chatinput").value)
{
// Invalid... Box is empty
}
The = assigns a value whereas == checks whether the values are equal.
Just offering an alternative, not trying to steal thunder ...
Create an isEmpty function to reuse on a variety of items.
function isEmpty(val){
return ((val !== '') && (val !== undefined) && (val.length > 0) && (val !== null));
}
Then you can apply it to whatever element you want:
if(!isEmpty(chatinput)){
// hooray its got a value!
}
Not exactly original, its the concept stolen from PHP, but it comes in handy a lot.

jquery check variable values

In jQuery I have the following 4 variables.
var add
var city
var state
var zip
I need to check to see that any one of the above have a value.
If none have a value that is OK. If all of them have a value that is OK.
Just need to check that at least one of them do not have a value.
Not sure what is the most efficient way of doing this.
var check = [ add, city, state, zip ].every( function ( v ) { return !!v } )
Just for the sake of showing off.
Explaination: the every method loops through all the array and returns false if one of the conditions returns false and stops immediately the loop. If all the loops return true, true is returned.
PS: v is for "variable".
var check = (function(a, b, c, d) {
return !!a && !!b && !!c && !!d;
}(add, city, state, zip));
console.log(check);
another method... lets learn some new techniques today!
this will actually check to see if the value is not false. anything else is ok (strings, numerics, TRUE).
Simply
if (yourVar)
{
// if yourVar has value then true other wise false.
}
Hope thats what you required..
to check i a variable has a value assign it to it you can do:
var myVar
....
if (typeof myVar === 'undefined'){
// here goes your code if the variable doesn't have a value
}
if(!add || !city || !state || !zip) {
console.log('exists var with no value');
}
if( add.length == 0 || zip.length == 0 || city.length == 0 || state.length == 0) {
alert("at least one of the variables has no value");
}; else if (add.length == 0 & zip.length == 0 & city.length == 0 & state.length == 0) {
alert("all of the variables are empty");
}; else { alert("okay"); }

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