How to find out if a Javascript variable has certain characters in it

Question

We have a quick order form which take in the product code (sku) and returns the product and enters a quantity of 1.

What we want to happen is any SKU that starts with EN9 we want the Quantity to be set to 0.

I have tried to work this out for myself but seem to be going no where as i have very minimum javascript experience.

This is the code which set everything

 var _parent = $j(this).parent().parent().parent();
 var _productid = $j(this).find('.prodid').val();
 var _sku = $j(this).find('.sku').html();
 var _name = $j(this).find('.name').html();
 var _price = $j(this).find('.pprice').val();
 var _temp_name = _name;
 _temp_name = _temp_name.replace(/(<([^>]+)>)/ig,"");
 _parent.find('.txt-sku').html(_sku);
 _parent.find('.txt-pcode').val(_temp_name);
 _parent.find('.txt-qty').val(1);
 _parent.find('.pname').html(_name);
 _parent.find('.pqty').html(_price);
 _parent.find('.btn-addcart').attr('alt', _productid);
 $j('#allid').val($j('#allid').val()+','+_productid);
 $j(this).parent().hide();
 _key = '';

I can see _parent.find('.txt-qty').val(1); sets the qty to 1 so i assumed i would have to wrap an IF statement around this.

I tried

 if ( _sku == ('EN9)){
 _parent.find('.txt-qty').val(1);}
else{
 _parent.find('.txt-qty').val(0);
}

But with no luck. SO i change -sku to .sku but still no luck. If anyone could help it would be much appreciated.

Answer 1

I would use indexOf

Something like

if ( _sku.indexOf('EN9') > -1) {
 _parent.find('.txt-qty').val(0);}
else{
 _parent.find('.txt-qty').val(1);
}

This would set your quantity to 0 if EN9 is anywhere in the SKU.

If you need it at the start, specifically, check for the return of indexOf being 0 (I think should work).

if ( _sku.indexOf('EN9') == 0) {
 _parent.find('.txt-qty').val(0);}
else{
 _parent.find('.txt-qty').val(1);
}

• art-solopov: Just a quick comment: according to MDN, ES6 will have the String.prototype.startsWith method.
• Adam Allen: I had to change this a little bit to if ( _sku.indexOf('EN9') < 1) {} But it works perfect :) thank you

Answer 2

You can use indexOf to check if a strings starts with another string, and then set the value accordingly

var qty = _sku.indexOf('EN9') === 0 ? '0' : '1';
_parent.find('.txt-qty').val(qty);

Answer 3

 if ( _sku == ('EN9)){

This is a messed up statement, as evidenced by the lack of sensible coloring here. :)

You want to check if _sku starts with EN9. You can do that by checking if the first 3 characters are equal to that:

if (_sku.slice(0,3) == 'EN9') {}