5 min. read time
1. ( + ) Symbol is Important
Let us take an example:
var x = 2 + 8;
var x = 2 + “8”;
This code will evaluate to “28” as the string and the plus symbol translates to a concatenation symbol. The submission values as input and the user input can be evaluated as a string.
So try using this code instead of the above one. Here, you convert the string value to an integer first.
Var x = 2 + parseInt (“8” , 2);
When you do this in the code, the string value is parse to the integer value and the addition function is performed.
2. The Use of “IF” Statement Incorrectly
Let’s take an example:
Var x = 2;
if (x == 2)
According to this entry, the evaluation will be x is equal to 2. And the result stands 2. But what in case the web developer makes a typo error? You can take the following code:
var x = 0;
if (x = 2)
See Also : Expert Tips For Angular Development
3. Undefined and Null Functions
The following code will give you an error if the object is undefined:
if (object !== null && typeof object !==”undefined”)
The object is undefined first, then identify if it’s null.
If (typeof object !== “undefined” && object !== null)
4. Named Objects Indexes as Arrays
The arrays use numeric integer indexes where web developers can also use objects similar to arrays but objects uses named indexes. If you attempt using a named index in an array then your code will return the wrong result.
The Following Array:
var color = [ ];
color  = “pink”;
color  = “purple”;
color  = “blue”;
var x = color, length;
var y = color ;
Here, the color with the name is created by assigning colors to the first three indexes. Further, the evaluation of the length and assigning of the first color to the variable y is done. The evaluation of variable x is 3 and the variable y contains “pink”. Array uses numeric integers and thus when you take an object, the result may be wrong.
5. No Scope for Block Level
In other scripting languages, you can easily create a loop structure through a variable. The loop is created through the variable and it is destroyed once the loop exists.