General

True when the value is absent, and false for any present value of any type. It is the same test as x == none; use whichever reads better.

isNone(x: any) -> bool

Returns

bool

First value

bar 0, whatever its arguments

version 1
study("Warmup shading", overlay = true)

slow = sma(close, 200)
background(isNone(slow) ? fade(gray, 90) : none)
plot(slow, "SMA 200", orange)

Remarks. isNone always answers true or false, from bar 0, whatever its argument. That is why it is safe as a guard on the left of and: in not isNone(x) and x > 5, the comparison runs only when x is present.

Order matters for which side runs, not for the answer. not isNone(x) and x > 5 and x > 5 and not isNone(x) give the same result; isNone(x) and x > 5 is never true however you write it.

See also. orElse(), bar.isFirst

Returns x when it is present and fallback when it is absent. Both must be the same type: orElse(close, "none") is OS3011. Use it where a missing value should count as something definite, such as a zero in a running total, or a label to show when the host did not state a fact.

orElse(x: T, fallback: T) -> T

Returns

T

First value

as soon as the earlier of x or fallback is present

version 1
study("Cumulative volume", format = "volume")

var total = 0.0
// Without orElse, one bar with no volume would make the total absent for good.
total += orElse(volume, 0)
plot(total, "Volume since the first bar", silver, style = "area")

Remarks. The result is present as soon as either argument is. A fallback hides warmup, which is the point in a running total and a trap in a signal: orElse(rsi(close, 14), 50) plots a flat 50 for the first bars, and a rule that trades on it treats those bars as real readings. Keep the absent value where a decision depends on it.

See also. isNone(), sumSkip(), avgSkip()

Turns a value into text, for a label, a table cell or an alert message. With one argument it takes any value; with a second, decimals, it writes a number with exactly that many digits after the point.

text(x: any) -> string
text(x: number, decimals: number) -> string

Returns

string

First value

bar 0

version 1
study("Close and ATR", overlay = true)

a = atr(14)
if bar.isLast
    msg = chart.symbol + " closed at " + text(close, 2) + ", ATR " + text(a, 2)
    draw.label(time, high, msg, textColor = white)

text(x, decimals) rounds halves away from zero and always writes plain digits, never an exponent: text(1234.5, 0) is "1235", text(-2.5, 0) is "-3" and text(2.5, 2) is "2.50". decimals must be a whole number.

Remarks. The two forms treat none differently. text(none) is the four letters "none", which is useful while debugging. text(x, 2) with an absent x is none, and so is any string it is joined to with +, so guard a message during warmup, as the page's first example does with isNone().

A decimal that looks like a half is not always stored as one. 1.005 is held as a number a hair below it, so text(1.005, 2) is "1.00", not "1.01".

See also. str.padLeft(), date.format(), cell()

Reads a number out of a string, and gives none when the string is not a number. Its most common use is a setting typed as text, such as a list of price levels in one input.

toNumber(s: string) -> number

Returns

number

First value

bar 0

version 1
study("Distance to the nearest level", precision = 2)

raw = input("22000, 22500, 23000", "Levels, separated by commas")

var levels: array<number> = []
if bar.isFirst
    for part in str.split(raw, ",")
        value = toNumber(part)
        if not isNone(value)
            push(levels, value)

nearest = none
for lvl in levels
    if isNone(nearest) or abs(close - lvl) < abs(close - nearest)
        nearest = lvl

plot(close - nearest, "Distance to the nearest level")

Remarks. It takes a string: toNumber(close) is OS3011. Always test the result with isNone() before you rely on it, as the example does, because a typing slip in a setting gives none rather than an error.

See also. text(), str.split(), str.trim()

Turns a bool that may be absent into a definite one: none becomes false, and true and false stay as they are. Use it where a condition computed during warmup must read as a plain false rather than unknown.

toBool(x: any) -> bool

Returns

bool

First value

bar 0, whatever its arguments

version 1
study("Trend flag", overlay = true)

ema50 = ema(close, 50)
above = toBool(close > ema50)    // false, not none, while the EMA warms up

panel = table("Trend", 1, 2, position = "topRight")
if bar.isLast
    cell(panel, 0, 0, "Above the 50 EMA")
    cell(panel, 0, 1, text(above))

Remarks. The difference shows wherever none would otherwise travel: not (close > ema50) is none during warmup, while not toBool(close > ema50) is true. Choose deliberately, because a warmup bar that reads as false is a claim about the market that nobody measured.

It is not a way to read a number as a condition; there is no truthiness (no rule that treats 0 as false) in the language. In release 0.5.0 the compiler accepts a number or a string here, and the result is false whatever the value, so toBool(1) is false. Write the comparison you mean, such as n != 0. The call is spelled toBool because bool is a type name and cannot be called: bool(x) is OS1019.

See also. isNone(), text()