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lookup

Find value in dictionary by key

Since R2023b

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    Syntax

    value = lookup(d,key)
    value = lookup(d,key,FallbackValue=fallback)

    Description

    value = lookup(d,key) returns the value corresponding to key in dictionary, d. If no entry corresponds to key then lookup throws an error.

    value = lookup(d,key) is equivalent to value = d(key).

    example

    value = lookup(d,key,FallbackValue=fallback) specifies a fallback value to return if key is not found in d.

    The lookup function does not validate fallback unless a fallback value is required. An error is not thrown unless key is not found, even if lookup is invalid.

    example

    Examples

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    Open Live Script

    Create a dictionary containing several key-value pairs.

    names = ["Unicycle" "Bicycle" "Tricycle"];
wheels = [1 2 3];
d = dictionary(wheels,names)
    d =

  dictionary (double --> string) with 3 entries:

    1 --> "Unicycle"
    2 --> "Bicycle"
    3 --> "Tricycle"

    Look up a value.

    v = lookup(d,1)
    v = 
"Unicycle"
    Open Live Script

    Create a dictionary containing several key-value pairs.

    names = ["Unicycle" "Bicycle" "Tricycle"];
wheels = [1 2 3];
d = dictionary(wheels,names)
    d =

  dictionary (double --> string) with 3 entries:

    1 --> "Unicycle"
    2 --> "Bicycle"
    3 --> "Tricycle"

    Look up a value with a fallback value if it is not found.

    v = lookup(d,[3,5],FallbackValue="Wheeled Vehicle")
    v = 1x2 string
    "Tricycle"    "Wheeled Vehicle"

    Input Arguments

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    Dictionary, specified as a dictionary object. If d is unconfigured, lookup throws an error.

    Key set, specified as an array. The data type of key must match or be convertible to the data type of keys in d.

    Fallback value, specified as a scalar containing the value to return if key is not found. The data type of fallback must match or be convertible to the data type of values in d. fallback is not validated unless key is not found.

    Example: FallbackValue="Wheeled Vehicle"

    Extended Capabilities

    Version History

    Introduced in R2023b

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    See Also

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