Javascript snippets
Set variable if it's undefined⚑
var x = (x === undefined) ? your_default_value : x;
Concatenate two arrays⚑
const arr1 = ["Cecilie", "Lone"];
const arr2 = ["Emil", "Tobias", "Linus"];
const children = arr1.concat(arr2);
To join more arrays you can use:
const arr1 = ["Cecilie", "Lone"];
const arr2 = ["Emil", "Tobias", "Linus"];
const arr3 = ["Robin"];
const children = arr1.concat(arr2,arr3);
Check if a variable is not undefined⚑
if(typeof lastname !== "undefined")
{
alert("Hi. Variable is defined.");
}
Select a substring⚑
'long string'.substring(startIndex, endIndex)
Round a number⚑
Math.round(2.5)
Remove focus from element⚑
document.activeElement.blur();
