Syntax

exchange.IO("toUnits", ...)

Converts a human-readable amount into an on-chain integer. The entire conversion is performed as an exact calculation on strings, without any floating-point arithmetic.


    
    
    
exchange.IO(k, amount, decimals)

Examples

Convert amounts of USDC and ETH.


    javascript
    
    
function main() {
    var USDC = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
    // Human-readable amount -> on-chain integer; the precision can be a number or a token address
    // (decimals is read automatically)
    Log(exchange.IO("toUnits", "1.5", 6))
    // Output: 1500000
    Log(exchange.IO("toUnits", "1.5", USDC))
    // Output: 1500000
    Log(exchange.IO("toUnits", "0.01", 18))
    // Output: 10000000000000000
    // On-chain integer -> human-readable amount
    Log(exchange.IO("fromUnits", "1500000", 6))
    // Output: 1.5
    var raw = exchange.IO("api", USDC, "balanceOf", exchange.IO("address"))
    Log("USDC balance:", exchange.IO("fromUnits", raw, USDC))
    // Reports an error when there are more decimal places than the precision, instead of silently
    // truncating
    Log(exchange.IO("toUnits", "1.0000001", 6), GetLastError())
}

Returns

Type	Description
string	Returns the on-chain integer (as a decimal string). When the number of decimal places exceeds the precision, it returns a null value and reports an error instead of silently truncating.

Arguments

Name	Type	Required	Description
k	string	Yes	Function of the `exchange.IO()` function. Setting it to `toUnits` indicates that the function is used to convert a human-readable amount into an on-chain integer.
amount	string / number	Yes	Human-readable amount, for example `"1.5"`. It is recommended to pass it as a string to avoid precision issues with the JavaScript number type; scientific notation is not supported.
decimals	number / string	Yes	Precision. You can pass a number (for example, 6 for USDC and 18 for ETH), or a token contract address, in which case the `decimals()` method of that token contract is called automatically to read the precision.