Programmatically use RGBa values in fillStyle in ?

Question

Using , I want to set the RGBa value of the rectangle using a variable.

for example:

ctx.fillStyle = \"rgba(32, 45, 21, 0         


        

Answer 1

You just need to concatenate the r_a variable to build the string correctly:

var r_a = 0.3; 
ctx.fillStyle = "rgba(32, 45, 21, " + r_a + ")";