JavaScript Arrays

Arrays

var myNumArray = [7,3,6,3,1,2]; // Create a new array with values console.log( myNumArray[0] ); // Access the first value (index 0) myNumArray[2] = 5 ; // Modify the third value (index 2)
  • An array is a collection of values which can be used like variables.
  • The values can be any data type, you can even have multiple types in the same array.
  • To access the value in an array, you put the array name followed by the slot position containing the value, where 0 is the first slot.
  • If you pass an array as a function parameter value, changes made to the array values within the function will remain changed out of the function.

Creating empty arrays

var myArray = []; // Create a new array with no values
  • The values can be added later.

Adding items to arrays

myArray.push("blue"); // Add the value "blue" to the end of the list

Getting length of arrays

var myLength = myArray.length;
  • This is useful to know so you don't try to access something outside the bounds of the array.

Challenge

Make an array of 10 strings and an array of 5 strings, write code that modifies the first item and displays the last item. Run the code once for each array.

Completed