StartsWith() [4/4]

bool System.String.StartsWith ( string value, StringComparison comparisonType )

inline

Definition at line 814 of file String.cs.

    {
        if ((object)value == null)
        {
            throw new ArgumentNullException("value");
        }
        if ((object)this == value)
        {
            CheckStringComparison(comparisonType);
            return true;
        }
        if (value.Length == 0)
        {
            CheckStringComparison(comparisonType);
            return true;
        }
        switch (comparisonType)
        {
        case StringComparison.CurrentCulture:
        case StringComparison.CurrentCultureIgnoreCase:
            return CultureInfo.CurrentCulture.CompareInfo.IsPrefix(this, value, GetCaseCompareOfComparisonCulture(comparisonType));
        case StringComparison.InvariantCulture:
        case StringComparison.InvariantCultureIgnoreCase:
            return CompareInfo.Invariant.IsPrefix(this, value, GetCaseCompareOfComparisonCulture(comparisonType));
        case StringComparison.Ordinal:
            if (Length < value.Length || _firstChar != value._firstChar)
            {
                return false;
            }
            if (value.Length != 1)
            {
                return SpanHelpers.SequenceEqual(ref Unsafe.As<char, byte>(ref GetRawStringData()), ref Unsafe.As<char, byte>(ref value.GetRawStringData()), (nuint)value.Length * (nuint)2u);
            }
            return true;
        case StringComparison.OrdinalIgnoreCase:
            if (Length < value.Length)
            {
                return false;
            }
            return Ordinal.EqualsIgnoreCase(ref GetRawStringData(), ref value.GetRawStringData(), value.Length);
        default:
            throw new ArgumentException(SR.NotSupported_StringComparison, "comparisonType");
        }
    }

References System.String._firstChar, System.String.CheckStringComparison(), System.comparisonType, System.Globalization.CultureInfo.CurrentCulture, System.Globalization.Ordinal.EqualsIgnoreCase(), System.String.GetCaseCompareOfComparisonCulture(), System.String.GetRawStringData(), System.Globalization.CompareInfo.Invariant, System.String.Length, System.SR.NotSupported_StringComparison, System.SpanHelpers.SequenceEqual(), and System.value.