dylangrech92 / seotoolbox

Consider adding curly braces around all statements when they are executed conditionally. This is optional if there is only one statement, but leaving them out can lead to unexpected behaviour if another statement is added later.

Consider:

if (a > 0)
    b = 42;

If you or someone else later decides to put another statement in, only the first statement will be executed.

if (a > 0)
    console.log("a > 0");
    b = 42;

In this case the statement b = 42 will always be executed, while the logging statement will be executed conditionally.

if (a > 0) {
    console.log("a > 0");
    b = 42;
}

ensures that the proper code will be executed conditionally no matter how many statements are added or removed.

This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed.

To learn more about declaring variables in Javascript, see the MDN.

When iterating over the keys of an object, this includes not only the keys of the object, but also keys contained in the prototype of that object. It is generally a best practice to check for these keys specifically:

var someObject;
for (var key in someObject) {
    if ( ! someObject.hasOwnProperty(key)) {
        continue; // Skip keys from the prototype.
    }

    doSomethingWith(key);
}

This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed.

To learn more about declaring variables in Javascript, see the MDN.

This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed.

To learn more about declaring variables in Javascript, see the MDN.

Consider adding curly braces around all statements when they are executed conditionally. This is optional if there is only one statement, but leaving them out can lead to unexpected behaviour if another statement is added later.

Consider:

if (a > 0)
    b = 42;

If you or someone else later decides to put another statement in, only the first statement will be executed.

if (a > 0)
    console.log("a > 0");
    b = 42;

In this case the statement b = 42 will always be executed, while the logging statement will be executed conditionally.

if (a > 0) {
    console.log("a > 0");
    b = 42;
}

ensures that the proper code will be executed conditionally no matter how many statements are added or removed.

This check looks for variables that are declared in multiple lines. There may be several reasons for this.

In the simplest case the variable name was reused by mistake. This may lead to very hard to locate bugs.

If you want to reuse a variable for another purpose, consider declaring it at or near the top of your function and just assigning to it subsequently so it is always declared.