backbone.jsHow do I use a backbone.js comparator to compare two values?

A comparator is a function in Backbone.js that allows you to compare two values. To use a comparator, you need to define a function that takes two parameters and returns either a negative value, a positive value, or 0 if the two values are equal. For example:

function compareValues(a, b) {
  if (a < b) {
    return -1;
  } else if (a > b) {
    return 1;
  } else {
    return 0;
  }
}

The compareValues function takes two parameters, a and b, and compares them. If a is less than b, the function returns a negative value. If a is greater than b, the function returns a positive value. If a is equal to b, the function returns 0.

Once the comparator is defined, you can use it in Backbone.js to compare two values. For example:

var val1 = 5;
var val2 = 10;

var comparison = compareValues(val1, val2);
console.log(comparison); // Output: -1

In the above example, the compareValues function is used to compare val1 and val2. Since val1 is less than val2, the function returns -1.

The following are the parts of the code and their explanations:

• function compareValues(a, b): This is the function definition for the comparator. It takes two parameters, a and b, and compares them.

• if (a < b) {: This is an if statement that checks if a is less than b. If it is, the code inside the if block is executed.

• return -1;: This is the return statement that returns -1 if a is less than b.

• else if (a > b) {: This is an else if statement that checks if a is greater than b. If it is, the code inside the else if block is executed.

• return 1;: This is the return statement that returns 1 if a is greater than b.

• else {: This is an else statement that is executed if a is equal to b.

• return 0;: This is the return statement that returns 0 if a is equal to b.

• var comparison = compareValues(val1, val2);: This is the line of code that calls the compareValues function and stores the result in the comparison variable.

• console.log(comparison);: This is the line of code that prints the value of the comparison variable to the console.

Helpful links

• Backbone.js Comparator Documentation

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