get 3 point from decimal in swift code example

Example 1: format decimal place swift

let tip: Double = 15.2847320
let tipText: String = String(format: "%.2f", tip)
// %.2f for two decimal places

Example 2: xcode truncate number of decimal places of double

//Multiply the double you want to round by 10^(the number of decimal place precision you want), use the "round()" function, then divide by that number again

let x = 1.23556789
let y = Double(round(1000*x)/1000)
print(y)  // 1.236