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When to use '=' or ':'

When to use and how to apply​

I have always come across this question when entering the JavaScript world so I think it might be useful for someone else :]

Well basically the = (assignment symbol) and : work together and for a better explanation here is an example:

The use of the two dots is basically to represent an object

var fruits = {
  banana: {
    color: 'yellow',
  },
};

And with an object, you can navigate between the levels of keys and values

fruits.banana.color; // yellow

So whenever you use a key in an object, you assign a value to it, using the two dots :

The = means to assign some value to a variable. It can be an object or any value you want.

Condicionals​

There are other uses, for example in conditional variables:

const color = arguments.length > 0 ? arguments[0] : 'black';

In the above example, assuming that this code is inside a function, you are saying: that if the number of arguments is greater than zero the variable "color" will be equal to the first argument, otherwise, it will be equal to "black"

The "if/else" is represented by the colon

See more on:

Labels​

There are also labels, implemented with EcmaScript, take a look:

References​